Proportioning Valves

[vindinot]

Heads up, I’ve spent days tracking down a proportioning valve for my V2500 Suburban while rebuilding the front and rear brakes. Instead of rolling the dice at junkyards, I found a company called MOCA AUTOPARTS that offers them, likely another Chinese manufacturer where it all comes down to the quality control testing before packaging. I haven’t found any complaints about their parts, though I haven’t been able to contact them directly since they have many resellers. I’m buying from one of them but will be using my old bracket.

https://www.wehaw.com/proportioning-valves-c-8_9_21_3219.htm

Also the P-valves from Carolina Trucks are the same as those sold on eBay and Amazon but way overpriced. For anyone wanting to keep their original P-valve, there’s also a site with rebuild kits and pictures showing how it’s done.

Home | Muscle Car Research LLC

www.musclecarresearch.com

 

[Goldie Driver]

Heads up, I’ve spent days tracking down a proportioning valve for my V2500 Suburban while rebuilding the front and rear brakes. Instead of rolling the dice at junkyards, I found a company called MOCA AUTOPARTS that offers them, likely another Chinese manufacturer where it all comes down to the quality control testing before packaging. I haven’t found any complaints about their parts, though I haven’t been able to contact them directly since they have many resellers. I’m buying from one of them but will be using my old bracket.

https://www.wehaw.com/proportioning-valves-c-8_9_21_3219.htm

Also the P-valves from Carolina Trucks are the same as those sold on eBay and Amazon but way overpriced. For anyone wanting to keep their original P-valve, there’s also a site with rebuild kits and pictures showing how it’s done.

Home | Muscle Car Research LLC

www.musclecarresearch.com

Let us know how it works !

But, to be safe, hold on to that OE one. You may need it in a year or so.

Thanks for the links and best of luck.

Britt

 

[Old Guy Bill]

I'd say they are all the same...

 

[Blue Ox]

Also the P-valves from Carolina Trucks are the same as those sold on eBay and Amazon but way overpriced. For anyone wanting to keep their original P-valve, there’s also a site with rebuild kits and pictures showing how it’s done.

Home | Muscle Car Research LLC

www.musclecarresearch.com

Great resource. Thanks for the info.

 

[Ricko1966]

I'd say they are all the same...

They aren't. Just in 86 alone the factory used at least 4 different combination valves,depending on different brake options, vehicle weight, and engine installed. There's a chart on here somewhere that shows the different biases.

https://www.gmsquarebody.com/threads/rear-brakes-locking-up-information-for-you.48473/#post-1037560

 

[Keith Seymore]

I think he meant "the quality of the re-pops is all the same".

At least that's what I am hoping. Because you are correct. Different GVW, wheelbase and brake systems all could have a different meter/split/slope pressures.

K

 

[Old Guy Bill]

I think he meant "the quality of the re-pops is all the same".

At least that's what I am hoping. Because you are correct. Different GVW, wheelbase and brake systems all could have a different meter/split/slope pressures.

K

Yes, exactly what I meant about the quality of the widely available units on Amazon, etc...
I contacted the Muscle Car Research guy when I was rebuilding my truck.
He didn't have a kit for the valve on my truck, but sent me some common
o-rings for them.
Yes, there were many, many, different ones designed for many, many vehicles.
I've never taken the original one apart, it's badly corroded.
I used one from LMC I believe.. still working.

 

[Broken85]

I have replaced four or five of these. All were leaking and all were OEM. Replaced three with units from Napa, one from EBay and the last from Amazon. None of them are leaking ……..yet..

 

[Fastduramax]

Adjustable unit from Willwood problem solved...

 

[FreeTruck]

Are all the ports on the factory one threaded for 3/8 - 24 fittings?

 

[Old Guy Bill]

It's been discussed several times here... a SEARCH would've shown this.
It's not just a proportioning valve, it's a "combination" valve.
It has the ability to warn the driver if there's a failure.
The manual ones can't do that.

 

[Blue Ox]

It's been discussed several times here... a SEARCH would've shown this.
It's not just a proportioning valve, it's a "combination" valve.
It has the ability to seal off the front or rear brake fluid and warn the driver if there's a failure.
The manual ones can't do that.

1000% on what you're saying, except that valve doesn't seal off a failed section.

They're inherently isolated. But I've never had a failure where the failed section didn't dump all the fluid.

 

[FreeTruck]

It's been discussed several times here... a SEARCH would've shown this.
It's not just a proportioning valve, it's a "combination" valve.
It has the ability to seal off the front or rear brake fluid and warn the driver if there's a failure.
The manual ones can't do that.

True true. The truth is, I searched for "who's the crustiest know-it-all on the Squarebody.com forum" and AI indicated it was you. So I thought I'd bait you into coming out of hiding. Congratulations, you played yourself. Jokes aside, if Google doesn't give a straight answer what makes you think the forum is going to do it?

Just to humor you, I went ahead and tried the forum's search and sure enough, when I searched "everywhere" for what the common size brake line fittings were, I got only three resulting threads, only one of which had to do with brakes.

 

[Old Guy Bill]

True true. The truth is, I searched for "who's the crustiest know-it-all on the Squarebody.com forum" and AI indicated it was you. So I thought I'd bait you into coming out of hiding. Congratulations, you played yourself. Jokes aside, if Google doesn't give a straight answer what makes you think the forum is going to do it?

Just to humor you, I went ahead and tried the forum's search and sure enough, when I searched "everywhere" for what the common size brake line fittings were, I got only three resulting threads, only one of which had to do with brakes.

I wasn't replying to you... if I was I would've "quoted" you, as I did in this post. It's old school Forum activity.
the original post is about sourcing this brake component, and how it operates.
I could've walked out to the garage and looked at an old valve to see the fitting size but now nah...
Start something with someone else.. I don't have the time

 

[Keith Seymore]

True true. The truth is, I searched for "who's the crustiest know-it-all on the Squarebody.com forum" and AI indicated it was you. So I thought I'd bait you into coming out of hiding. Congratulations, you played yourself. Jokes aside, if Google doesn't give a straight answer what makes you think the forum is going to do it?

Just to humor you, I went ahead and tried the forum's search and sure enough, when I searched "everywhere" for what the common size brake line fittings were, I got only three resulting threads, only one of which had to do with brakes.

Phew.

I figgered it would be me.

K