73 C20 front brake issue, The right front caliper will not retract, causing the wheel to almost lock.

[Goldie Driver]

Yup, Keith is correct. So in this application the forward reservoir is for front brakes. That is the first place to look for a leak.

Went and looked at the '79. Sho 'nuff.

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Pardon the mess

Please define forward. That set up is like mine and the big line in the front (forward) part of the master cylinder feeds the rears.

 

[Keith Seymore]

Doesn't matter.

The large reservoir always feeds the front discs, regardless of how it is positioned. The small reservoir works the drums, because less fluid is required for the wheel cylinders.

It's the only way it can work.

K

 

[Goldie Driver]

Doesn't matter.

The large reservoir always feeds the front discs, regardless of how it is positioned. The small reservoir works the drums, because less fluid is required for the wheel cylinders.

It's the only way it can work.

K

Why does the drum side use a larger line diameter? That logic puzzles me.

Thanks !

 

[Keith Seymore]

I do not know. My Chevelle was the same way.

When I converted to manual brakes I made them both the same size, for convenience sake.

Pressure is pressure, and exerts the same force on all sides of the vessel regardless of diameter.

Maybe idiot proofing, so they don't get confused in the assembly plant?

K

 

[Ricko1966]

I do not know. My Chevelle was the same way.

When I converted to manual brakes I made them both the same size, for convenience sake.

Pressure is pressure, and exerts the same force on all sides of the vessel regardless of diameter.

Maybe idiot proofing, so they don't get confused in the assembly plant?

K

Larger diameter means more volume,maybe the difference is to reduce time to overcome the standoff valve. Engineers look at milliseconds,us dummies don't know how. EDIT when I said dummies I meant me.

 

[Grit dog]

Pretty universal. Bigger reservoir and bigger brake line = front. Also not hard to visually trace to verify.

 

[Radiohead]

But the reservoirs are the same volume.

 

[Goldie Driver]

Pretty universal. Bigger reservoir and bigger brake line = front. Also not hard to visually trace to verify.

Oh, so close.
Bigger reservoir = front Brakes. Bigger line on my square(cast iron square reservoirs as a whole ?) = rears.

 

[Goldie Driver]

But the reservoirs are the same volume.

It looks that way on the outside. Look at the below - the reservoir on the left side is the one closest to where it bolts to the booster and is for the fronts.

https://www.gmsquarebody.com/threads/rear-brakes-locking-up.46675/post-1000177

 

[Radiohead]

But the reservoirs are the same volume.

A ha ha ha ha ha, not so fast self. They are not the same. Had a sunny 50° day today, so it was time to finish up the brake rubber program. Of course the painted master cylinder was bled and installed as well. Now since I am eternally curious, as part of the gravity bleed for the front half, I took note of which part went down and.... [drum roll please] the half closest to the booster lost level. I'm confused as to what I had originally said and without looking to see, I'm just going to amend any brain flatulence I may have broadcast.

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The paint still hasn't fully cured. Note to self, don't use engine paint in the PNW winter unless one is fully prepared to heat up the article to evaporate the solvent in a timely manner. Lol.


So there you go. The three hoses are here

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These are Delco branded hoses, and both fronts required a bit of massaging to get the area for the banjo bolt to sit in the proper aspect off the caliper to not run into suspension components. Not impossible, but ffs, why couldn't they get the bends right before hand. Lazy crap, but I made them work. Also, the passenger side fitting at the frame end was clocked wrong with the one way hole. Managed to change the control arm clamp positioning enough to make it work, but there's still a weird dip in how it is routed. Time will tell if the hose will accept the odd torsional, I don't like it.


In case you've never looked inside a front brake hose, here's a view of what you're missing. Easy to see how one can plug with little effort.

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It looks way smaller in real life. Never clamp a rubber line when removing a caliper, way too easy to crush the rubber and ruin it.

 

[Ricko1966]

A ha ha ha ha ha, not so fast self. They are not the same. Had a sunny 50° day today, so it was time to finish up the brake rubber program. Of course the painted master cylinder was bled and installed as well. Now since I am eternally curious, as part of the gravity bleed for the front half, I took note of which part went down and.... [drum roll please] the half closest to the booster lost level. I'm confused as to what I had originally said and without looking to see, I'm just going to amend any brain flatulence I may have broadcast.

You must be registered for see images attach

The paint still hasn't fully cured. Note to self, don't use engine paint in the PNW winter unless one is fully prepared to heat up the article to evaporate the solvent in a timely manner. Lol.


So there you go. The three hoses are here

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

These are Delco branded hoses, and both fronts required a bit of massaging to get the area for the banjo bolt to sit in the proper aspect off the caliper to not run into suspension components. Not impossible, but ffs, why couldn't they get the bends right before hand. Lazy crap, but I made them work. Also, the passenger side fitting at the frame end was clocked wrong with the one way hole. Managed to change the control arm clamp positioning enough to make it work, but there's still a weird dip in how it is routed. Time will tell if the hose will accept the odd torsional, I don't like it.


In case you've never looked inside a front brake hose, here's a view of what you're missing. Easy to see how one can plug with little effort.

You must be registered for see images attach

It looks way smaller in real life. Never clamp a rubber line when removing a caliper, way too easy to crush the rubber and ruin it.

You know AC Delco now has three pricing and quality tiers now. 2 are just your standard parts store offshore garbage that everyone else sells. So they quit losing sales to the lowball chain stores.

 

[xm20k]

A ha ha ha ha ha, not so fast self. They are not the same. Had a sunny 50° day today, so it was time to finish up the brake rubber program. Of course the painted master cylinder was bled and installed as well. Now since I am eternally curious, as part of the gravity bleed for the front half, I took note of which part went down and.... [drum roll please] the half closest to the booster lost level. I'm confused as to what I had originally said and without looking to see, I'm just going to amend any brain flatulence I may have broadcast.

You must be registered for see images attach

The paint still hasn't fully cured. Note to self, don't use engine paint in the PNW winter unless one is fully prepared to heat up the article to evaporate the solvent in a timely manner. Lol.


So there you go. The three hoses are here

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

These are Delco branded hoses, and both fronts required a bit of massaging to get the area for the banjo bolt to sit in the proper aspect off the caliper to not run into suspension components. Not impossible, but ffs, why couldn't they get the bends right before hand. Lazy crap, but I made them work. Also, the passenger side fitting at the frame end was clocked wrong with the one way hole. Managed to change the control arm clamp positioning enough to make it work, but there's still a weird dip in how it is routed. Time will tell if the hose will accept the odd torsional, I don't like it.


In case you've never looked inside a front brake hose, here's a view of what you're missing. Easy to see how one can plug with little effort.

You must be registered for see images attach

It looks way smaller in real life. Never clamp a rubber line when removing a caliper, way too easy to crush the rubber and ruin it.

Was swelling shut, should be bigger. What it should look like.

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[Turbo4whl]

In case you've never looked inside a front brake hose, here's a view of what you're missing. Easy to see how one can plug with little effort.

You must be registered for see images attach

That hose is a good example of the bladder failing completely, and ready to become a check valve for holding pressure in the disc piston, or wheel cylinder.

 

[Keith Seymore]

"Hose becoming a check valve".

Like when escalators become stairs.

K

 

[Grit dog]

Oh, so close.
Bigger reservoir = front Brakes. Bigger line on my square(cast iron square reservoirs as a whole ?) = rears.

Maybe I’m thinking typical disc disc setup? Idk. Fortunately both my squares came with new/great condition brake systems and I haven’t touched either, other than throwing new fluid at them occasionally.