Back from the dead, but figured I would try it.
I have an issue where the left front and right rear run hotter (by feel and temp gun ) than the others.
Is our system on an X pattern, or just front to back ?
Loosening the master cylinder from the power booster seemed to have no effect on the lf caliper, and the rears are new including drums as of Saturday.
I thought I had both rears pretty even with a slight drag.
Thanks!
Britt
Probably not your problem, but just something to look at.
On the hot RR drum, what kind of condition are the contact pads in - and are they lubricated?
Look closely at the condition of the contact pads on the backing plate. Although there is not any relative
rotary motion between the brake shoes and the backing plate, there is a certain degree of linear motion that occurs - as when the wheel cylinders force the shoes out against the drums. Even though the shoes are held tightly against the backing plates (by the mounting/hold down springs), the brakes are engaged by hydraulic pressure so they rarely (if ever) stick on the way out.
But when the brakes are released, the only force that returns them to the free wheel position is what is provided by the return springs. For that reason, the inboard edges of the shoes must be able to move freely across the 6 contact pads. If the pads are trashed they tend to prevent the shoes from fully releasing. In that case, it is possible that the linings then stay in contact with the drums causing heat and premature wear. Or, as noted below, if the pads are modified - in an attempt to restore the smooth surface - this results in misalignment and grabby/noisy brakes:
You must be registered for see images attach
Nickel Never-seize seems to work best as a lubricant - and it stays put between brake jobs:
You must be registered for see images attach
From the GM service manual:
BACKING-PLATE INSPECTION
Contact Pads - Clean the contact pads thoroughly and verify they are not burred or grooved. Burrs may be removed with very light sanding. If the contact pads are grooved the backing-plate should be replaced.
You must be registered for see images attach
NOTE: Grooved contact pads may cause the rear brakes to drag or stick. If you attempt to remove the grooves by grinding or filing, the new shoes/linings will not line up correctly with the drum. This may result in the problems noted above.
The contact pads should be coated with a high temperature silicone lubricant prior to reinstalling the shoes/linings.
Mounting Bolts - Verify the mounting bolts are secure. A loose backing-plate will cause the rear brakes to be very sensitive or grabby.
On the hot LF disc brake, while there could be any number of causes, a good place to start is at the contact points - are the slide surfaces smooth and lubricated? Use a file to clean the surfaces shown below and apply Never-seize:
You must be registered for see images attach
You must be registered for see images attach
