Dragging brakes on a 1991 Corolla

[Gasoline Fumes]

My parents' 1991 Toyota Corolla wagon has a weird brake issue. Before driving the car, the front wheels spin just fine. After driving the car, the front wheels are very difficult to turn and the wheels are hot. Driver's side is hotter and harder to turn. Calipers do not stick after pumping the brake when cold.

What's causing this? Brake hoses? Master cylinder? Calipers appear to be in great shape and at least the driver's side is not seized. I didn't inspect the passenger's side caliper very well since it's less of a problem. Both calipers were replaced with rebuilt calipers a few years ago.

[vinny1989]

Possibly warped brake discs?

[Old Mechanic]

If the calipers are sticking you can verify it by breaking loose the bleeder on the suspect caliper, just a little bit to see if there is any residual pressure in the system.

There shouldn't be any, and the caliper will spin more freely if there is any residual pressure.

If there is any residual pressure then you have two possible sources.

Bad master cylinder that is not allowing the pressure created to be released.

Bad front brake hoses, which have swollen shut internally and act like check valves, not allowing the pressure created to be relieved by the fluid moving back into the master reservoir.

If the calipers are or the "floating type" with a single piston on one side and pins that allow the caliper to move when the pressure is applied. When the pins freeze the caliper can not move and it will cause the brakes to stick.

The last problem is the most common when you have the single piston (only one side of the rotor). An additional symptom of the sticking floating pins is uneven brake pad wear.

regards
Mech

[bgd73]

a perfect error no doubt.

something playing with heat of runtime.

Calipers changed not long ago must mean newer fluid? old fluid can do something crazy. Does not stay its actual size in heat anymore when old..expands on its own.

the pins sticking used to be common on big rotors.

the single pots are nearly impossible to blame. large area given for the fluid to take it easy (I am 23 years in maine on originals)...absolutely no end in sight. I can even appply the handbrake without the leverage...

transverse does send some powerful energies parellel to the crank, anyhting with lubes gets challenged. Maybe repack bearings even after finding error. Drop temps for the area. feel cvs after runtime (outer).. just needs to calm down with cool.

[autoteach]

Originally Posted by Old Mechanic

If the calipers are sticking you can verify it by breaking loose the bleeder on the suspect caliper, just a little bit to see if there is any residual pressure in the system.

There shouldn't be any, and the caliper will spin more freely if there is any residual pressure.

If there is any residual pressure then you have two possible sources.

Bad master cylinder that is not allowing the pressure created to be released.

Bad front brake hoses, which have swollen shut internally and act like check valves, not allowing the pressure created to be relieved by the fluid moving back into the master reservoir.

If the calipers are or the "floating type" with a single piston on one side and pins that allow the caliper to move when the pressure is applied. When the pins freeze the caliper can not move and it will cause the brakes to stick.

The last problem is the most common when you have the single piston (only one side of the rotor). An additional symptom of the sticking floating pins is uneven brake pad wear.

regards
Mech

+1

On another note that may not be affecting you (as I doubt you have ABS), I had an ABS module that got crystallized brake fluid (OLD!!!) in it that clogged the ports so that it held pressure. It should have been replaced, but the owner would not even buy one from the junk yard. We cleaned it and it worked?! (that is a question/statement). But MECH is right, check those things out.

[Gasoline Fumes]

Thanks everybody! The pins didn't seem to be sticking and pad wear looked pretty even. I guess I should be thinking about replacing the hoses first? I haven't gotten a chance to look at the car again, I'll try the bleeders after a drive.

[MetroMPG]

I had a similar problem with one of my cars (Accord, I think).

It was the brake hoses acting as a check valve as Mech described. They would very slowly release pressure as the car sat parked, so it would roll properly when cold, and then act up again on the next drive.

I'd never heard of that particular problem before it happened to me.

[some_other_dave]

This is familiar to owners of some older cars. (40-year-old aircooled classics, for example.) Most often, the brake hoses are acting as a check-valve as noted. Crack a bleeder just like Mech said, if the brake releases at that point you know that pressure is being trapped in the caliper, and the #1 suspect is the brake hose.

If that doesn't make the caliper release, then you continue searching for other problems, like calipers that need rebuilding or replacing again.

-soD