Can anyone tell me what this is??

[ButchM]

It was not uncommon to have that hydraulic-over-electrical controller, drip on your leg or shoes; they were however, the only thing going for lighter vehicles, although surge brakes - which are NOT integrated into the vehicle's hydraulic brakes, were used occasionally.

Tapping into a single-cylinder master cylinder to operate the hydraulic-electric brake controller was rapidly made illegal even though Pep-Boys and Western Auto decided --- if they couldn't sell them in California, they'd sell them to other states.

They slowly became illegal if not by becoming the cause of brake pedals dropping to the floor in a panic stop; remember --- this is a single piston master cylinder system! This is what/where it was designed to operate.

It was never advertised (TTBOMK) as a trailer brake controller on dual-master cylinder systems.

I tried one once --- it wasn't good and the brake pedal was always a lot lower than it should be --- and it would trip the overcenter switch if used in a hard stop.

Surge brakes are still in use --- legally --- in California but only on boat trailers as they are a sealed system, not electric, and can work well if some maintenance is performed.

If I used any big words that you - (as a collective, not any particular individual) - can't understand, let me know, and I can use sock puppets to act out this post for you.

Surfer
First off please refer to my post last week and reread the entire thread.
An example may illustrate, have you ever been in a group setting and someone asks "why do politicians suck so bad?" and there is that guy who pipes in with "well actually, just like an internal combustion engine, when the piston moves down it doesn't really SUCK in air, the higher atmospheric pressure outside pushes the air into the engine due to the pressure differential across the intake tract"? While technically correct, it wasn't answering the question that was asked or even in the spirit of the conversation.
BTW, telling people on here that being a retired mechanic is your superpower is kinda implying that you believe you know more than most here, doubtful.
If you read through the various threads you will realize that there are many people here with decades and decades of non-professional mechanic experience that have learned the "old fashioned" way. As you may, or may not know, before the advent of the interweb and computers/scanners we learned by trial and error or asking someone (same as here but in person) for advice/help, or some combination of both. Most of the problems/questions posed here although new to the poster, have been experienced many times by someone previously. That is why this is an awesome resource for "young-uns" getting into what are now called square bodies, as well as un not so young-uns who come upon new problems. Cringe.... I bought an 84 K10 new at a Chev dealership. They're looking for assistance and guidance, not fire and brimstone from a pulpit.
As for the whole sock puppet thing.... LOLOLOL

 

[ButchM]

It was not uncommon to have that hydraulic-over-electrical controller, drip on your leg or shoes; they were however, the only thing going for lighter vehicles, although surge brakes - which are NOT integrated into the vehicle's hydraulic brakes, were used occasionally.

Tapping into a single-cylinder master cylinder to operate the hydraulic-electric brake controller was rapidly made illegal even though Pep-Boys and Western Auto decided --- if they couldn't sell them in California, they'd sell them to other states.

They slowly became illegal if not by becoming the cause of brake pedals dropping to the floor in a panic stop; remember --- this is a single piston master cylinder system! This is what/where it was designed to operate.

It was never advertised (TTBOMK) as a trailer brake controller on dual-master cylinder systems.

I tried one once --- it wasn't good and the brake pedal was always a lot lower than it should be --- and it would trip the overcenter switch if used in a hard stop.

Surge brakes are still in use --- legally --- in California but only on boat trailers as they are a sealed system, not electric, and can work well if some maintenance is performed.

If I used any big words that you - (as a collective, not any particular individual) - can't understand, let me know, and I can use sock puppets to act out this post for you.

Did CA outlaw the surge brakes on U-Haul trailers?

 

[RanchWelder]

I did an hour of research to find anything about the hydraulic controllers not being allowed legally, and i cannot find anything. The only thing I have found is that the Kelsey-Hayes company went through business changing of hands around when they stopped making the last unit (90s), and by time it did anything new in the controller world, it went to the electric-automatic (with accelerometers and stuff)
And the company restructured again in 2023. I sent them an email asking if they by chance know what the reason is. we will see if they respond or what they say.

I was digging through Federal Register listings and Code of Federal Regulations for these things, and nothing comes up.

It's above your pay grade to find the court cases because of the Trade Association's heavy hand on this crap...dark Hand erased it from the internet.

Some of the operatives for that org are likely undecover here, arguing with you?
Nahhhhh, never....

You know if GM had to recall 450,000 over brake controllers, these simple stoopid resistors must have failed brilliantly in the auto parts hydro units with zero defect o-rings and stamped tin valve levers?

The threads were cut without 000.99999 capable CAD software and highly altered thread tollerance proprietary machinery in China? What could go wrong?

(The Auto CAD thread software was $6000.00 plug in module in 2000-2008. AC had to authorize you to be accepted into the "Safe and Approved Vendore's Team", in order to buy it though...)

Nah, they work great!

Spit on it and stick it in!

Cockroach never killed one yet, let alone a cold soda pop on that cheapo resistor controller? Nah.....

https://www.motortrend.com/news/201...rado-hd-medium-duty-trucks-recall-fire-hazard

3.8 Million bad brakes?
https://www.nbcnews.com/business/co...y-3-8m-pickups-suvs-fix-brake-issues-n1052356

Engines are good too:
https://www.hemmings.com/stories/gm-recall-calls-out-721k-trucks-and-suvs-for-v8-engine-failure/

Trust a foreign brake controller made by a minimally insured fly-by-night company because I'm a Redneck, daminit!

Those ikids in China/Indjuia/Mexicalli make good stuuuuf!

California is the problem, (but that's besides the point), although I love them West Coaster's, really I do... Something about the sun setting on the ocean makes them super hot women. (I'm from West Coast FLA, so I know the tuned down Gulf of America bikini sunset version.)

It's where they ship all the cheap stuff that bother's me.
Why do them CAL importer's get all the imports, duties and terrifs money?
I want some terrif's money too.

On a lighter note:
Please move AG?
You deserve to be free and un-taxed and less poisoned in the Fly-Over States.
We run 4WD's , fish, hunt Deer/Elk day and night.

Like both ya'll's arguments though, only one of you could honestly be trusted to service my brake system. Lot's of good ideas get the shin dig though.

Bet me 450,000 recalls they are not safe for real people with real liability?

The best engineers get it wrong with billions to spend.

It's all a crap shoot.

The electric systems seem to work well if installed "into a factory harness by a certified professional", like AG.

Just don't drop your soda pop on it either, OK?

You win Auroragirl just because you are Super Cool, in my guestimate.
Shreck video really hit a nerve, huhuhuh.

Ya'll give the lady some space?
She's just teasin'.

*** No disrespect to "sock puppet's" was implied or should be interpreted while reading this comment. Honestly don't know any SP\s, so if I offended one, did not mean too.***

 

[AuroraGirl]

It's above your pay grade to find the court cases because of the Trade Association's heavy hand on this crap...dark Hand erased it from the internet.

Some of the operatives for that org are likely undecover here, arguing with you?
Nahhhhh, never....

You know if GM had to recall 450,000 over brake controllers, these simple stoopid resistors must have failed brilliantly in the auto parts hydro units with zero defect o-rings and stamped tin valve levers?

The threads were cut without 000.99999 capable CAD software and highly altered thread tollerance proprietary machinery in China? What could go wrong?

(The Auto CAD thread software was $6000.00 plug in module in 2008. They had to authorize you to be accepted into the "Safe and Approved Vendore's Team", in order to buy it though...)

Nah, they work great!

Spit on it and stick it in!

Cockroach never killed one yet, let alone a cold soda pop on that cheapo resistor controller? Nah.....

https://www.motortrend.com/news/201...rado-hd-medium-duty-trucks-recall-fire-hazard

3.8 Million bad brakes?
https://www.nbcnews.com/business/co...y-3-8m-pickups-suvs-fix-brake-issues-n1052356

Engines are good too:
https://www.hemmings.com/stories/gm-recall-calls-out-721k-trucks-and-suvs-for-v8-engine-failure/

I trust a foreign brake controller made by a minimally insured fly by night company because I'm a Redneck, daminit! Those ikids in China/Indjuia make good stuuuuf!

California is the problem, (but that's besides the point), although I love them West Coaster's, really I do...
It's where they ship all the cheap stuff that bother's me.
Why do they get all the import, duties and terrfi's money?
I want some too.

On a lighter note:
Please move AG?
You deserve to be free and un-taxed and less poisoned in the Fly-Over States.

Like both ya'll's arguments though, only one of you could honestly be trusted to service my brake system. Lot's of good ideas get the shin dig though.

Bet me 450,000 recalls they are not safe for real people with real liability?

The best engineers get it wrong with billions to spend.

It's all a crap shoot.

The electric systems seem to work well if installed "into a factory harness by a certified professional", like AG.

Just don't drop your soda pop on it either, OK?

You win Auroragirl just because you are Super Cool, in my guestimate.
Shreck video really hit a nerve, huhuhuh.

Ya'll give the lady some space?
She's just teasin'.

i dont live in cali lol

You must be registered for see images

You must be registered for see images attach

xc_hide_links_from_guests_guests_error_hide_media

 

[RanchWelder]

Boneyard makes the cut.
Keep cold, drink fresh.

Knew you were Super Intelligent O/C Blond.

Green Flag!

 

[59840Surfer]

Did CA outlaw the surge brakes on U-Haul trailers?

C'mon, Butch --- you didn't say that did you? --- because it's not the same system.

Surge brakes are self-contained ON the trailer tongue.

Hydraulic-over-Electric controllers are inside the cab so the driver can manually apply the trailer brakes.

Pay attention --- it helps a lot.

 

[59840Surfer]

It's above your pay grade to find the court cases because of the Trade Association's heavy hand on this crap...dark Hand erased it from the internet.

Some of the operatives for that org are likely undecover here, arguing with you?
Nahhhhh, never....

You know if GM had to recall 450,000 over brake controllers, these simple stoopid resistors must have failed brilliantly in the auto parts hydro units with zero defect o-rings and stamped tin valve levers?

The threads were cut without 000.99999 capable CAD software and highly altered thread tollerance proprietary machinery in China? What could go wrong?

(The Auto CAD thread software was $6000.00 plug in module in 2000-2008. AC had to authorize you to be accepted into the "Safe and Approved Vendore's Team", in order to buy it though...)

Nah, they work great!

Spit on it and stick it in!

Cockroach never killed one yet, let alone a cold soda pop on that cheapo resistor controller? Nah.....

https://www.motortrend.com/news/201...rado-hd-medium-duty-trucks-recall-fire-hazard

3.8 Million bad brakes?
https://www.nbcnews.com/business/co...y-3-8m-pickups-suvs-fix-brake-issues-n1052356

Engines are good too:
https://www.hemmings.com/stories/gm-recall-calls-out-721k-trucks-and-suvs-for-v8-engine-failure/

Trust a foreign brake controller made by a minimally insured fly-by-night company because I'm a Redneck, daminit!

Those ikids in China/Indjuia/Mexicalli make good stuuuuf!

California is the problem, (but that's besides the point), although I love them West Coaster's, really I do... Something about the sun setting on the ocean makes them super hot women. (I'm from West Coast FLA, so I know the tuned down Gulf of America bikini sunset version.)

It's where they ship all the cheap stuff that bother's me.
Why do them CAL importer's get all the imports, duties and terrifs money?
I want some terrif's money too.

On a lighter note:
Please move AG?
You deserve to be free and un-taxed and less poisoned in the Fly-Over States.
We run 4WD's , fish, hunt Deer/Elk day and night.

Like both ya'll's arguments though, only one of you could honestly be trusted to service my brake system. Lot's of good ideas get the shin dig though.

Bet me 450,000 recalls they are not safe for real people with real liability?

The best engineers get it wrong with billions to spend.

It's all a crap shoot.

The electric systems seem to work well if installed "into a factory harness by a certified professional", like AG.

Just don't drop your soda pop on it either, OK?

You win Auroragirl just because you are Super Cool, in my guestimate.
Shreck video really hit a nerve, huhuhuh.

Ya'll give the lady some space?
She's just teasin'.

*** No disrespect to "sock puppet's" was implied or should be interpreted while reading this comment. Honestly don't know any SP\s, so if I offended one, did not mean too.***

1. Brake System Design and Proportioning Valve Behavior:
   • The proportioning valve’s role in dual master cylinder systems (introduced in the U.S. around 1967 for safety, per federal regulations like FMVSS 105 <NOTE: FEDERAL here>) was to ensure balanced braking and detect hydraulic failures.
   • When a significant pressure differential occurred—such as fluid being diverted to the Kelsey-Hayes controller—the valve would shift, activating the BRAKE light.
   • This is consistent with standard automotive texts from the era, like the Motor Auto Repair Manual (1970s editions), which describe how combination valves trigger warning lights when pressure imbalances exceed design thresholds.
   • A corollary here is any aftermarket brake modification that disrupts hydraulic balance, such as poorly installed brake boosters or mismatched master cylinders, which similarly caused BRAKE light illumination and reduced braking efficiency. For example, discussions on automotive forums (e.g., Chevytalk.org or similar vintage car communities) often mention aftermarket brake controllers causing warning light issues in 1970s vehicles due to hydraulic interference.
2. Historical Context of Trailer Brake Controllers:
   • The Kelsey-Hayes controller’s design was outdated for dual master cylinder systems, as it was engineered for single-circuit systems with simpler hydraulics.
   • Technical literature from the 1970s, such as SAE papers on brake system safety, often highlighted compatibility issues with aftermarket accessories.
   • While not being supported by a specific SAE paper on the Kelsey-Hayes unit, general discussions from that period (e.g., SAE J885, Human Factors in Brake System Design) note that add-on brake controllers could interfere with modern hydraulic systems, leading to certification failures by state inspectors like CalDOT.
   • A direct corollary is the Tekonsha brake controller, a contemporary of Kelsey-Hayes, which also faced scrutiny for compatibility issues with newer vehicles.
   • Vintage trailer enthusiast forums (e.g., RV.net archives) mention similar problems where older controllers triggered warning lights or failed inspections due to hydraulic mismatches.
3. CalDOT Inspection Standards:
   • California’s Department of Transportation (CalDOT) and the California Highway Patrol (CHP), which oversaw brake inspections, enforced strict standards under the California Vehicle Code (CVC), particularly Sections 26450–26458, covering brake system requirements.
   • These mandated that brake systems maintain balanced performance and that warning systems (like the BRAKE light) function correctly.
   • If the Kelsey-Hayes controller caused the BRAKE light to stay on due to a false failure signal, it would fail inspection, as it indicated a malfunctioning or unsafe brake system.
   • A corollary is found in inspection failures for other hydraulic brake issues, such as leaking wheel cylinders or mismatched brake lines, which also trigger the proportioning valve and BRAKE light.
   • Field CalDOT/EPA Inspectors' experiences aligns with CHP inspection guidelines from the 1970s, which emphasized rejecting vehicles with any warning light activation that wasn’t resolved by correcting the underlying issue.
4. Real-World Anecdotes:
   • While not formal documentation, anecdotes from mechanics and inspectors on platforms like X or automotive restoration groups corroborate the field inspector's experience.
   • For instance, posts on X from vintage Chevy van enthusiasts (e.g., @Vanner69, 2023) describe aftermarket brake controllers causing hydraulic issues, including BRAKE light activation, on 1970s vehicles.
   • These align with validated observations of customers bringing in vehicles with persistent BRAKE light issues tied to the Kelsey-Hayes unit.
   • Another corollary is the experience of trailer towing communities in the 1970s, who often retrofitted controllers like the Kelsey-Hayes onto newer vehicles, only to encounter hydraulic problems.
   • Publications like Trailer Life (1970s issues) warned about the risks of using older controllers on dual-circuit systems, citing issues as noted above.
5. Technical Mechanism of the Failure:
   • The Kelsey-Hayes controller’s reliance on fluid volume to actuate its variable resistor likely “stole” fluid from one circuit (typically the rear brake circuit in a front/rear split system). This reduced pressure in that circuit, causing the proportioning valve to shift and activate the BRAKE light, as described.
   • This is mechanically similar to a real hydraulic leak, which explains why the system interpreted it as a failure.
   • Automotive repair manuals of the era, like those from Chilton’s, note that any accessory drawing excessive fluid from a dual master cylinder could mimic a leak, triggering the warning system.
   • A corollary is the behavior of early anti-lock brake systems (ABS) in the 1980s, which sometimes caused false BRAKE light activation when hydraulic modulators drew fluid unevenly, confusing the proportioning valve.
   • While not identical, this reflects a similar principle of hydraulic interference.

Specific Documentation​

Direct references to the Kelsey-Hayes controller’s issues with dual master cylinders are scarce in modern sources, as it’s a niche topic tied to 1970s automotive technology ... this is because of still-possible litigation from old lawsuits that failed to excoriate the manufacturer.
Most web and X searches yield general discussions of trailer brake controllers or vintage vehicle restoration rather than specific CalDOT inspection failures.
However, firsthand accounts by inspectors, combined with the technical principles of dual master cylinder systems and proportioning valves, strongly support the collaborative issue as described. Access to old CalDOT inspection manuals or CHP guidelines from the 1970s, would be secondary and might contain specific references to aftermarket controller incompatibilities.

Conclusion​

• Inadequate Brake Force Distribution: The controller's demand for fluid volume interfered with the dual master cylinder's ability to properly distribute hydraulic pressure, reducing rear brake effectiveness.
• Safety Hazard: The diminished rear brake performance created a dangerous situation, as the vehicle couldn't achieve balanced braking, increasing stopping distances or risking loss of control.
• Non-Compliance with Standards: CalDOT regulations likely required brake systems to meet specific performance criteria, which the Kelsey-Hayes controller failed to do when paired with a dual-cylinder system due to its design limitations.
• Non-believers can eat sh|t and die.

 

[AuroraGirl]

1. Brake System Design and Proportioning Valve Behavior:
   • The proportioning valve’s role in dual master cylinder systems (introduced in the U.S. around 1967 for safety, per federal regulations like FMVSS 105 <NOTE: FEDERAL here>) was to ensure balanced braking and detect hydraulic failures.
   • When a significant pressure differential occurred—such as fluid being diverted to the Kelsey-Hayes controller—the valve would shift, activating the BRAKE light.
   • This is consistent with standard automotive texts from the era, like the Motor Auto Repair Manual (1970s editions), which describe how combination valves trigger warning lights when pressure imbalances exceed design thresholds.
   • A corollary here is any aftermarket brake modification that disrupts hydraulic balance, such as poorly installed brake boosters or mismatched master cylinders, which similarly caused BRAKE light illumination and reduced braking efficiency. For example, discussions on automotive forums (e.g., Chevytalk.org or similar vintage car communities) often mention aftermarket brake controllers causing warning light issues in 1970s vehicles due to hydraulic interference.
2. Historical Context of Trailer Brake Controllers:
   • The Kelsey-Hayes controller’s design was outdated for dual master cylinder systems, as it was engineered for single-circuit systems with simpler hydraulics.
   • Technical literature from the 1970s, such as SAE papers on brake system safety, often highlighted compatibility issues with aftermarket accessories.
   • While not being supported by a specific SAE paper on the Kelsey-Hayes unit, general discussions from that period (e.g., SAE J885, Human Factors in Brake System Design) note that add-on brake controllers could interfere with modern hydraulic systems, leading to certification failures by state inspectors like CalDOT.
   • A direct corollary is the Tekonsha brake controller, a contemporary of Kelsey-Hayes, which also faced scrutiny for compatibility issues with newer vehicles.
   • Vintage trailer enthusiast forums (e.g., RV.net archives) mention similar problems where older controllers triggered warning lights or failed inspections due to hydraulic mismatches.
3. CalDOT Inspection Standards:
   • California’s Department of Transportation (CalDOT) and the California Highway Patrol (CHP), which oversaw brake inspections, enforced strict standards under the California Vehicle Code (CVC), particularly Sections 26450–26458, covering brake system requirements.
   • These mandated that brake systems maintain balanced performance and that warning systems (like the BRAKE light) function correctly.
   • If the Kelsey-Hayes controller caused the BRAKE light to stay on due to a false failure signal, it would fail inspection, as it indicated a malfunctioning or unsafe brake system.
   • A corollary is found in inspection failures for other hydraulic brake issues, such as leaking wheel cylinders or mismatched brake lines, which also trigger the proportioning valve and BRAKE light.
   • Field CalDOT/EPA Inspectors' experiences aligns with CHP inspection guidelines from the 1970s, which emphasized rejecting vehicles with any warning light activation that wasn’t resolved by correcting the underlying issue.
4. Real-World Anecdotes:
   • While not formal documentation, anecdotes from mechanics and inspectors on platforms like X or automotive restoration groups corroborate the field inspector's experience.
   • For instance, posts on X from vintage Chevy van enthusiasts (e.g., @Vanner69, 2023) describe aftermarket brake controllers causing hydraulic issues, including BRAKE light activation, on 1970s vehicles.
   • These align with validated observations of customers bringing in vehicles with persistent BRAKE light issues tied to the Kelsey-Hayes unit.
   • Another corollary is the experience of trailer towing communities in the 1970s, who often retrofitted controllers like the Kelsey-Hayes onto newer vehicles, only to encounter hydraulic problems.
   • Publications like Trailer Life (1970s issues) warned about the risks of using older controllers on dual-circuit systems, citing issues as noted above.
5. Technical Mechanism of the Failure:
   • The Kelsey-Hayes controller’s reliance on fluid volume to actuate its variable resistor likely “stole” fluid from one circuit (typically the rear brake circuit in a front/rear split system). This reduced pressure in that circuit, causing the proportioning valve to shift and activate the BRAKE light, as described.
   • This is mechanically similar to a real hydraulic leak, which explains why the system interpreted it as a failure.
   • Automotive repair manuals of the era, like those from Chilton’s, note that any accessory drawing excessive fluid from a dual master cylinder could mimic a leak, triggering the warning system.
   • A corollary is the behavior of early anti-lock brake systems (ABS) in the 1980s, which sometimes caused false BRAKE light activation when hydraulic modulators drew fluid unevenly, confusing the proportioning valve.
   • While not identical, this reflects a similar principle of hydraulic interference.

Specific Documentation​

Direct references to the Kelsey-Hayes controller’s issues with dual master cylinders are scarce in modern sources, as it’s a niche topic tied to 1970s automotive technology ... this is because of still-possible litigation from old lawsuits that failed to excoriate the manufacturer.
Most web and X searches yield general discussions of trailer brake controllers or vintage vehicle restoration rather than specific CalDOT inspection failures.
However, firsthand accounts by inspectors, combined with the technical principles of dual master cylinder systems and proportioning valves, strongly support the collaborative issue as described. Access to old CalDOT inspection manuals or CHP guidelines from the 1970s, would be secondary and might contain specific references to aftermarket controller incompatibilities.

Conclusion​

• Inadequate Brake Force Distribution: The controller's demand for fluid volume interfered with the dual master cylinder's ability to properly distribute hydraulic pressure, reducing rear brake effectiveness.
• Safety Hazard: The diminished rear brake performance created a dangerous situation, as the vehicle couldn't achieve balanced braking, increasing stopping distances or risking loss of control.
• Non-Compliance with Standards: CalDOT regulations likely required brake systems to meet specific performance criteria, which the Kelsey-Hayes controller failed to do when paired with a dual-cylinder system due to its design limitations.
• Non-believers can eat sh|t and die.

No... no im not letting you get off that easy
I was advocating civility and wanted to hear what you had to say, because genuine interest and reasonable people can disagree or discuss topics civil-y or at least maturely (admittedly, not everyone to you was that).

But your claim was they are unsafe and illegal.
I just read your whole post twice and theres a lot of If, possibly, sometimes but not any hard facts.

Kelsey hayes and Tekonsha and maybe others had produced these units into the 1990s and my gmt800 owners manual has a spec for allowable volume to be used by a controller of this type., your facts arent facting

 

[PrairieDrifter]

No... no im not letting you get off that easy
I was advocating civility and wanted to hear what you had to say, because genuine interest and reasonable people can disagree or discuss topics civil-y or at least maturely (admittedly, not everyone to you was that).

But your claim was they are unsafe and illegal.
I just read your whole post twice and theres a lot of If, possibly, sometimes but not any hard facts.

Kelsey hayes and Tekonsha and maybe others had produced these units into the 1990s and my gmt800 owners manual has a spec for allowable volume to be used by a controller of this type., your facts arent facting

100% straight out of his inspector pamphlet lololol.

We need a source. It's 2025.

If you can't back up your claim, you're literally just shittinoutyourass. He literally just gave all the same crap he's been spewing but edited his typing format

 

[PrairieDrifter]

1. Brake System Design and Proportioning Valve Behavior:
   • The proportioning valve’s role in dual master cylinder systems (introduced in the U.S. around 1967 for safety, per federal regulations like FMVSS 105 <NOTE: FEDERAL here>) was to ensure balanced braking and detect hydraulic failures.
   • When a significant pressure differential occurred—such as fluid being diverted to the Kelsey-Hayes controller—the valve would shift, activating the BRAKE light.
   • This is consistent with standard automotive texts from the era, like the Motor Auto Repair Manual (1970s editions), which describe how combination valves trigger warning lights when pressure imbalances exceed design thresholds.
   • A corollary here is any aftermarket brake modification that disrupts hydraulic balance, such as poorly installed brake boosters or mismatched master cylinders, which similarly caused BRAKE light illumination and reduced braking efficiency. For example, discussions on automotive forums (e.g., Chevytalk.org or similar vintage car communities) often mention aftermarket brake controllers causing warning light issues in 1970s vehicles due to hydraulic interference.
2. Historical Context of Trailer Brake Controllers:
   • The Kelsey-Hayes controller’s design was outdated for dual master cylinder systems, as it was engineered for single-circuit systems with simpler hydraulics.
   • Technical literature from the 1970s, such as SAE papers on brake system safety, often highlighted compatibility issues with aftermarket accessories.
   • While not being supported by a specific SAE paper on the Kelsey-Hayes unit, general discussions from that period (e.g., SAE J885, Human Factors in Brake System Design) note that add-on brake controllers could interfere with modern hydraulic systems, leading to certification failures by state inspectors like CalDOT.
   • A direct corollary is the Tekonsha brake controller, a contemporary of Kelsey-Hayes, which also faced scrutiny for compatibility issues with newer vehicles.
   • Vintage trailer enthusiast forums (e.g., RV.net archives) mention similar problems where older controllers triggered warning lights or failed inspections due to hydraulic mismatches.
3. CalDOT Inspection Standards:
   • California’s Department of Transportation (CalDOT) and the California Highway Patrol (CHP), which oversaw brake inspections, enforced strict standards under the California Vehicle Code (CVC), particularly Sections 26450–26458, covering brake system requirements.
   • These mandated that brake systems maintain balanced performance and that warning systems (like the BRAKE light) function correctly.
   • If the Kelsey-Hayes controller caused the BRAKE light to stay on due to a false failure signal, it would fail inspection, as it indicated a malfunctioning or unsafe brake system.
   • A corollary is found in inspection failures for other hydraulic brake issues, such as leaking wheel cylinders or mismatched brake lines, which also trigger the proportioning valve and BRAKE light.
   • Field CalDOT/EPA Inspectors' experiences aligns with CHP inspection guidelines from the 1970s, which emphasized rejecting vehicles with any warning light activation that wasn’t resolved by correcting the underlying issue.
4. Real-World Anecdotes:
   • While not formal documentation, anecdotes from mechanics and inspectors on platforms like X or automotive restoration groups corroborate the field inspector's experience.
   • For instance, posts on X from vintage Chevy van enthusiasts (e.g., @Vanner69, 2023) describe aftermarket brake controllers causing hydraulic issues, including BRAKE light activation, on 1970s vehicles.
   • These align with validated observations of customers bringing in vehicles with persistent BRAKE light issues tied to the Kelsey-Hayes unit.
   • Another corollary is the experience of trailer towing communities in the 1970s, who often retrofitted controllers like the Kelsey-Hayes onto newer vehicles, only to encounter hydraulic problems.
   • Publications like Trailer Life (1970s issues) warned about the risks of using older controllers on dual-circuit systems, citing issues as noted above.
5. Technical Mechanism of the Failure:
   • The Kelsey-Hayes controller’s reliance on fluid volume to actuate its variable resistor likely “stole” fluid from one circuit (typically the rear brake circuit in a front/rear split system). This reduced pressure in that circuit, causing the proportioning valve to shift and activate the BRAKE light, as described.
   • This is mechanically similar to a real hydraulic leak, which explains why the system interpreted it as a failure.
   • Automotive repair manuals of the era, like those from Chilton’s, note that any accessory drawing excessive fluid from a dual master cylinder could mimic a leak, triggering the warning system.
   • A corollary is the behavior of early anti-lock brake systems (ABS) in the 1980s, which sometimes caused false BRAKE light activation when hydraulic modulators drew fluid unevenly, confusing the proportioning valve.
   • While not identical, this reflects a similar principle of hydraulic interference.

Specific Documentation​

Direct references to the Kelsey-Hayes controller’s issues with dual master cylinders are scarce in modern sources, as it’s a niche topic tied to 1970s automotive technology ... this is because of still-possible litigation from old lawsuits that failed to excoriate the manufacturer.
Most web and X searches yield general discussions of trailer brake controllers or vintage vehicle restoration rather than specific CalDOT inspection failures.
However, firsthand accounts by inspectors, combined with the technical principles of dual master cylinder systems and proportioning valves, strongly support the collaborative issue as described. Access to old CalDOT inspection manuals or CHP guidelines from the 1970s, would be secondary and might contain specific references to aftermarket controller incompatibilities.

Conclusion​

• Inadequate Brake Force Distribution: The controller's demand for fluid volume interfered with the dual master cylinder's ability to properly distribute hydraulic pressure, reducing rear brake effectiveness.
• Safety Hazard: The diminished rear brake performance created a dangerous situation, as the vehicle couldn't achieve balanced braking, increasing stopping distances or risking loss of control.
• Non-Compliance with Standards: CalDOT regulations likely required brake systems to meet specific performance criteria, which the Kelsey-Hayes controller failed to do when paired with a dual-cylinder system due to its design limitations.
• Non-believers can eat sh|t and die.

You already eatshit because that's all that comes out of your mouth, so go ahead and do the second part fuckinloser. You're a never was.

Not a single fact was stated by you. All opinion.

I bet you hotbox your own farts

 

[ButchM]

C'mon, Butch --- you didn't say that did you? --- because it's not the same system.

Surge brakes are self-contained ON the trailer tongue.

Hydraulic-over-Electric controllers are inside the cab so the driver can manually apply the trailer brakes.

Pay attention --- it helps a lot.

Surfer
Before you post a comment, you should read the question and your post, if you can understand the words.
You said surge brakes (and yes, I know what they are) were only legal in CA in boat trailers. Last time I rented a dual axle U-Haul trailer (in CA) it had surge brakes, ya I still remember what they are, do you? So my question stands; did they outlaw surge brakes on U-Haul cargo trailers?
Maybe you should take your own advice and pay attention, it would help us all.

 

[ButchM]

1. Brake System Design and Proportioning Valve Behavior:
   • The proportioning valve’s role in dual master cylinder systems (introduced in the U.S. around 1967 for safety, per federal regulations like FMVSS 105 <NOTE: FEDERAL here>) was to ensure balanced braking and detect hydraulic failures.
   • When a significant pressure differential occurred—such as fluid being diverted to the Kelsey-Hayes controller—the valve would shift, activating the BRAKE light.
   • This is consistent with standard automotive texts from the era, like the Motor Auto Repair Manual (1970s editions), which describe how combination valves trigger warning lights when pressure imbalances exceed design thresholds.
   • A corollary here is any aftermarket brake modification that disrupts hydraulic balance, such as poorly installed brake boosters or mismatched master cylinders, which similarly caused BRAKE light illumination and reduced braking efficiency. For example, discussions on automotive forums (e.g., Chevytalk.org or similar vintage car communities) often mention aftermarket brake controllers causing warning light issues in 1970s vehicles due to hydraulic interference.
2. Historical Context of Trailer Brake Controllers:
   • The Kelsey-Hayes controller’s design was outdated for dual master cylinder systems, as it was engineered for single-circuit systems with simpler hydraulics.
   • Technical literature from the 1970s, such as SAE papers on brake system safety, often highlighted compatibility issues with aftermarket accessories.
   • While not being supported by a specific SAE paper on the Kelsey-Hayes unit, general discussions from that period (e.g., SAE J885, Human Factors in Brake System Design) note that add-on brake controllers could interfere with modern hydraulic systems, leading to certification failures by state inspectors like CalDOT.
   • A direct corollary is the Tekonsha brake controller, a contemporary of Kelsey-Hayes, which also faced scrutiny for compatibility issues with newer vehicles.
   • Vintage trailer enthusiast forums (e.g., RV.net archives) mention similar problems where older controllers triggered warning lights or failed inspections due to hydraulic mismatches.
3. CalDOT Inspection Standards:
   • California’s Department of Transportation (CalDOT) and the California Highway Patrol (CHP), which oversaw brake inspections, enforced strict standards under the California Vehicle Code (CVC), particularly Sections 26450–26458, covering brake system requirements.
   • These mandated that brake systems maintain balanced performance and that warning systems (like the BRAKE light) function correctly.
   • If the Kelsey-Hayes controller caused the BRAKE light to stay on due to a false failure signal, it would fail inspection, as it indicated a malfunctioning or unsafe brake system.
   • A corollary is found in inspection failures for other hydraulic brake issues, such as leaking wheel cylinders or mismatched brake lines, which also trigger the proportioning valve and BRAKE light.
   • Field CalDOT/EPA Inspectors' experiences aligns with CHP inspection guidelines from the 1970s, which emphasized rejecting vehicles with any warning light activation that wasn’t resolved by correcting the underlying issue.
4. Real-World Anecdotes:
   • While not formal documentation, anecdotes from mechanics and inspectors on platforms like X or automotive restoration groups corroborate the field inspector's experience.
   • For instance, posts on X from vintage Chevy van enthusiasts (e.g., @Vanner69, 2023) describe aftermarket brake controllers causing hydraulic issues, including BRAKE light activation, on 1970s vehicles.
   • These align with validated observations of customers bringing in vehicles with persistent BRAKE light issues tied to the Kelsey-Hayes unit.
   • Another corollary is the experience of trailer towing communities in the 1970s, who often retrofitted controllers like the Kelsey-Hayes onto newer vehicles, only to encounter hydraulic problems.
   • Publications like Trailer Life (1970s issues) warned about the risks of using older controllers on dual-circuit systems, citing issues as noted above.
5. Technical Mechanism of the Failure:
   • The Kelsey-Hayes controller’s reliance on fluid volume to actuate its variable resistor likely “stole” fluid from one circuit (typically the rear brake circuit in a front/rear split system). This reduced pressure in that circuit, causing the proportioning valve to shift and activate the BRAKE light, as described.
   • This is mechanically similar to a real hydraulic leak, which explains why the system interpreted it as a failure.
   • Automotive repair manuals of the era, like those from Chilton’s, note that any accessory drawing excessive fluid from a dual master cylinder could mimic a leak, triggering the warning system.
   • A corollary is the behavior of early anti-lock brake systems (ABS) in the 1980s, which sometimes caused false BRAKE light activation when hydraulic modulators drew fluid unevenly, confusing the proportioning valve.
   • While not identical, this reflects a similar principle of hydraulic interference.

Specific Documentation​

Direct references to the Kelsey-Hayes controller’s issues with dual master cylinders are scarce in modern sources, as it’s a niche topic tied to 1970s automotive technology ... this is because of still-possible litigation from old lawsuits that failed to excoriate the manufacturer.
Most web and X searches yield general discussions of trailer brake controllers or vintage vehicle restoration rather than specific CalDOT inspection failures.
However, firsthand accounts by inspectors, combined with the technical principles of dual master cylinder systems and proportioning valves, strongly support the collaborative issue as described. Access to old CalDOT inspection manuals or CHP guidelines from the 1970s, would be secondary and might contain specific references to aftermarket controller incompatibilities.

Conclusion​

• Inadequate Brake Force Distribution: The controller's demand for fluid volume interfered with the dual master cylinder's ability to properly distribute hydraulic pressure, reducing rear brake effectiveness.
• Safety Hazard: The diminished rear brake performance created a dangerous situation, as the vehicle couldn't achieve balanced braking, increasing stopping distances or risking loss of control.
• Non-Compliance with Standards: CalDOT regulations likely required brake systems to meet specific performance criteria, which the Kelsey-Hayes controller failed to do when paired with a dual-cylinder system due to its design limitations.
• Non-believers can eat sh|t and die.

Based on this blah blah blah of from the internet cut-and-paste pseudo-info, ad nauseum, I'm guessing you were a bicycle mechanic. Maybe you should spend some time wrenching on something with four wheels.

 

[bucket]

1. Brake System Design and Proportioning Valve Behavior:
   • The proportioning valve’s role in dual master cylinder systems (introduced in the U.S. around 1967 for safety, per federal regulations like FMVSS 105 <NOTE: FEDERAL here>) was to ensure balanced braking and detect hydraulic failures.
   • When a significant pressure differential occurred—such as fluid being diverted to the Kelsey-Hayes controller—the valve would shift, activating the BRAKE light.
   • This is consistent with standard automotive texts from the era, like the Motor Auto Repair Manual (1970s editions), which describe how combination valves trigger warning lights when pressure imbalances exceed design thresholds.
   • A corollary here is any aftermarket brake modification that disrupts hydraulic balance, such as poorly installed brake boosters or mismatched master cylinders, which similarly caused BRAKE light illumination and reduced braking efficiency. For example, discussions on automotive forums (e.g., Chevytalk.org or similar vintage car communities) often mention aftermarket brake controllers causing warning light issues in 1970s vehicles due to hydraulic interference.
2. Historical Context of Trailer Brake Controllers:
   • The Kelsey-Hayes controller’s design was outdated for dual master cylinder systems, as it was engineered for single-circuit systems with simpler hydraulics.
   • Technical literature from the 1970s, such as SAE papers on brake system safety, often highlighted compatibility issues with aftermarket accessories.
   • While not being supported by a specific SAE paper on the Kelsey-Hayes unit, general discussions from that period (e.g., SAE J885, Human Factors in Brake System Design) note that add-on brake controllers could interfere with modern hydraulic systems, leading to certification failures by state inspectors like CalDOT.
   • A direct corollary is the Tekonsha brake controller, a contemporary of Kelsey-Hayes, which also faced scrutiny for compatibility issues with newer vehicles.
   • Vintage trailer enthusiast forums (e.g., RV.net archives) mention similar problems where older controllers triggered warning lights or failed inspections due to hydraulic mismatches.
3. CalDOT Inspection Standards:
   • California’s Department of Transportation (CalDOT) and the California Highway Patrol (CHP), which oversaw brake inspections, enforced strict standards under the California Vehicle Code (CVC), particularly Sections 26450–26458, covering brake system requirements.
   • These mandated that brake systems maintain balanced performance and that warning systems (like the BRAKE light) function correctly.
   • If the Kelsey-Hayes controller caused the BRAKE light to stay on due to a false failure signal, it would fail inspection, as it indicated a malfunctioning or unsafe brake system.
   • A corollary is found in inspection failures for other hydraulic brake issues, such as leaking wheel cylinders or mismatched brake lines, which also trigger the proportioning valve and BRAKE light.
   • Field CalDOT/EPA Inspectors' experiences aligns with CHP inspection guidelines from the 1970s, which emphasized rejecting vehicles with any warning light activation that wasn’t resolved by correcting the underlying issue.
4. Real-World Anecdotes:
   • While not formal documentation, anecdotes from mechanics and inspectors on platforms like X or automotive restoration groups corroborate the field inspector's experience.
   • For instance, posts on X from vintage Chevy van enthusiasts (e.g., @Vanner69, 2023) describe aftermarket brake controllers causing hydraulic issues, including BRAKE light activation, on 1970s vehicles.
   • These align with validated observations of customers bringing in vehicles with persistent BRAKE light issues tied to the Kelsey-Hayes unit.
   • Another corollary is the experience of trailer towing communities in the 1970s, who often retrofitted controllers like the Kelsey-Hayes onto newer vehicles, only to encounter hydraulic problems.
   • Publications like Trailer Life (1970s issues) warned about the risks of using older controllers on dual-circuit systems, citing issues as noted above.
5. Technical Mechanism of the Failure:
   • The Kelsey-Hayes controller’s reliance on fluid volume to actuate its variable resistor likely “stole” fluid from one circuit (typically the rear brake circuit in a front/rear split system). This reduced pressure in that circuit, causing the proportioning valve to shift and activate the BRAKE light, as described.
   • This is mechanically similar to a real hydraulic leak, which explains why the system interpreted it as a failure.
   • Automotive repair manuals of the era, like those from Chilton’s, note that any accessory drawing excessive fluid from a dual master cylinder could mimic a leak, triggering the warning system.
   • A corollary is the behavior of early anti-lock brake systems (ABS) in the 1980s, which sometimes caused false BRAKE light activation when hydraulic modulators drew fluid unevenly, confusing the proportioning valve.
   • While not identical, this reflects a similar principle of hydraulic interference.

Specific Documentation​

Direct references to the Kelsey-Hayes controller’s issues with dual master cylinders are scarce in modern sources, as it’s a niche topic tied to 1970s automotive technology ... this is because of still-possible litigation from old lawsuits that failed to excoriate the manufacturer.
Most web and X searches yield general discussions of trailer brake controllers or vintage vehicle restoration rather than specific CalDOT inspection failures.
However, firsthand accounts by inspectors, combined with the technical principles of dual master cylinder systems and proportioning valves, strongly support the collaborative issue as described. Access to old CalDOT inspection manuals or CHP guidelines from the 1970s, would be secondary and might contain specific references to aftermarket controller incompatibilities.

Conclusion​

• Inadequate Brake Force Distribution: The controller's demand for fluid volume interfered with the dual master cylinder's ability to properly distribute hydraulic pressure, reducing rear brake effectiveness.
• Safety Hazard: The diminished rear brake performance created a dangerous situation, as the vehicle couldn't achieve balanced braking, increasing stopping distances or risking loss of control.
• Non-Compliance with Standards: CalDOT regulations likely required brake systems to meet specific performance criteria, which the Kelsey-Hayes controller failed to do when paired with a dual-cylinder system due to its design limitations.
• Non-believers can eat sh|t and die.

You know, you might have still had some kind of credibility here before you just made that elaborate post. But any credibility you might have still had just flew out the window.

It was a nice story of opinions, theories and other tall tales though. But there's one big thing here though... YOU JUST TOLD EVERYONE YOU WERE WRONG AND THAT YOU DID YOUR JOB AS AN INSPECTOR INCORRECTLY. I put that in all caps for you since you were likely not to bother reading it.

Nowhere in any of that was a law that forbid the use of those brake controllers. Nowhere in any of that was a statement that one of those brake controllers was an automatic failure of a safety inspection. By your very own statements, a vehicle with one of those controllers would fail a safety inspection ONLY IF it caused the brake warning lamp to be illuminated. Many times before, you stated that you would automatically fail any vehicle with one of those controllers because it was "illegal". Well I've got news for you. For every person that had an improperly balanced brake system due to one of those controllers (which by the way, you seem to have a fetish for singling out just the Kelsey Hayes brand. There were several more makers, in case you were unaware) there are oodles more of folks that ran those controllers and had a properly working and balanced brake system.

IN CONCLUSION:

You were wrong and you sucked at your job. In your time as a safety inspector, you helped give all inspectors a bad name as well.

You must be registered for see images attach

 

[Ricko1966]

You are not the only person on here that had an inspector license,nor are you the only one on here that was or is a tech. You and I had a problem before,you talked down your nose at everyone,rewrote part of what I'd already said brushed right past the important pieces. When I pointed it out you called me all kinds of names,accused me of eating boogers and starting fires( yes he really did do that) administrators had to go on and edit your post and make an example of yoo. Your last post has numerous inaccuracies in it I'm not going to waste my time arguing them with you. You need to learn you are not in fact smarter than everyone,you aren't even as smart as you think you are. I try very hard not to post on things you have posted on,because I don't want to deal with you,but this one has gone too far,I had to say something. Now go eat boogers and start fires,there administrator can edit that. I wish I had a copy of the tiraid where you called me everything under the son so everyone could see what a child you are. No its still not okay to install another whole fuse box branched off of 1 fused circuit in the original fuse box to power a fuel pump, electric choke,and other accessories. You need relays,even if you don't think so.