Technical 56 olds rear brakes get hot

Hello,

I have a 1956 oldsmobile super 88.
I have replaced everything in the brake system and now the rear brakes get hot.
I have adjusted the pedal, the rear adjusters, replaced all the hoses lines shoes drums and master cylinder.
After driving for around 10 miles the rear brakes become hot. They don't drag when cool but after they are hot and the car is raised you can feel the brakes dragging. I am completely out of ideas. The only thing I can think of that hasn't been tried is arcing the shoes or adjusting the pivot bolts. Do you think this could cause thr issues? Also I'm running c/10 rear drums instead of the kanter ones. Could this be thr issue?

Thanks,

Micah

 

Check the routing, and the slack of the E- ( parking ) - brake cable.
If not loose, there can be trouble.

 

Is there sufficient slack in the pedal to master? Too tight there can cause this when things heat up.

 

New brake shoe’s? Check to see if the shoe’s are not offset of the drum. The replacements today have the anchor pit notch in the wrong place.

 

Just back off the adjuster another click and try it, I've struck this with GM Holden (Autralian) vehicles..

 

I know you said you replaced all the hoses, but if it's only the rear brakes that drag, you could have gotten a new bad hose. When they start to drag, crack the rear bleeders a little and see if fluid shoots out. If that stops the dragging for a short time, when they start to drag again, crack the line going to the rear hose. If nothing much comes out, crack the side of the hose that goes to the wheel cylinders. If fluid shoots out , it's the hose.

 

Just a thought for posterity.
Brake issues are a common issue here and they all have a common theme, we like to do to much at once. We decide we’re going to upgrade or do maintenance and we fiddle with all the brake components at the same time and when we have problems we don’t know where to look. I’ve done this and in the future will not.

 

This. Can you explain more?

 

No pressure In line when opening bleeders

 

Cables are disconnected

 

Yes new shoes. Can you please explain more?

 

The shoe’s would be too high or too low. Therefore shoe’s can become wedged.

 

^ Seems this would show when the drums are installed...?

 

With a new drum yes. One that’s worn another story.

 

Maybe chamfer the leading and trailing edges of the brake shoes.
When I adjust the brakes I tighten the adjuster all the way as tight I can get them then back it off for freewheel and count the clicks then do the same on the other side backing off the same amount of clicks.

 

Johnny's suggestion is fascinating.
My 57 Pontanic does exactly the same thing.
I concluded that it must be a collapsed (new) rear brake hose, but now I am wondering.
I could not find shes locally so asked for 75 Scout shoes, supposed to be the same.
Hmmm.

 

It’s only something to look into first and foremost. Make a pointer of stiff wire secured to one of the wheel studs then bent to the outer edge of the shoe then turn hub/axle to see what’s going on.

 

When I had a similar problem, it was the master cylinder causing the brakes to tighten up, by keeping pressure when brake fluid expanded due to heat.

 

What does the contact area on the shoes look like? Contact location may be a clue.

Are the the top anchor pins adjustable to center the shoes?

Mentioned earlier the leading edges of both the primary & secondary shoes can be beveled if they are catching.

Are the shoes correct for your backing plates, there is a difference in the top notch location between GM and Ford/IHC Bendix style shoes.

 

Is there a residual valve in the rear brake circuit ? Could not be working correctly. Had that happen before.

 

When the brakes lock up jack up the stuck wheel, and turn backwards. If it unsticks the shoes are wedging into the drums. Then not centered correctly, or wrong or bent shoes.

 

Yes

Contact are looks to be top and bottom of both shoes.

I have not adjusted anchor bolts as they are very tight and look like they have never been adjusted.

I took the grinder to the leading edge.

I keep trying the same shoes from O'Reilly.
Maybe they are all wrong.

 

I replaced the master cylinder with one from kanter.

 

Are you also having a rear brake heating up situation?

 

Did you upgrade to disc brakes in the front? Same thing happened to my dad’s OT el Camino. Headers cooked the proportioning valve- replaced and relocated it and all is good.

 

No. 4 wheel drum manual brakes.

 

You know properly fitted shoes should contact in the middle of the shoe with some clearance at both ends. Sounds like you need to find a brake shop that will fit the shoes to the drums.

 

"Are you also having a rear brake heating up situation?"
Yes Sir, that would be the title of the thread

 

I'm using O'Reilly pn 228

75 scout takes O'Reilly pn 263.

Are you running through 263's and it's still getting hot?

 

Edit:
55-58 Pontiac = 71-73 Scout & 46-48 Olds per Raybestos.