More brake problems

[B-Co Kid]

i am having problems with my brake system. the brakes work, but if i get on the brakes, not slamming them, but not gradually either, my rear

wheels seem to lock up, and makes the tires screech as if i slammed on the brakes. I know the rear brakes lock up, bcuz at times when i put

it in drive, the truck wont move until i give it a lil gas. i have replaced brake shoes, i have new steel braided lines,

i have replaced the abs hydraulic unit. another problem, im sure its

all tied together, is that my abs light has been on for ages. ive pulled the codes and done the pin test. codes pointed to a bad or

defective isolation valve and to check the wiring on pin 13 (circuit 511 or something). which is why i replaced the abs hydraulics, and i checked the wiring, and i didnt see any bad wiring (pink-lt green). abs light is still on. where should i try next?? booster/master cylinder?? wheel cylinder??

 

[Krafty]

I would have done wheel cylinders when you did the rear shoes, at 10 bucks a side its the cheapest part to replace.

 

[Bully Bob]

Hi B-Co.,

As you prob. know., the front brakes do the majority of the stopping. (this is what keeps the rears from skidding)

What you describe is a safty issue & very dangerous. Both the locking up with pressure, & the staying locked after stop completed.

It's poss. you did something wrong., or there's a failing part in the system.

Throwing more parts at it now, may complicate things.

I would advise, at this point, getting it to a certified shop. "Bite the bullet" & pay to have it serviced/corrected.

An injury or damage could be far more expensive. :blush:

 

[Rons beast]

First correct the ABS problem. Then check that the primary and secondary shoes are installed corectly, as well as all the return springs and adjusters. Be sure the wheel cylinders and axel seals aren't leaking on the shoes. That would cause them to stick. If all is in order, make sure the shoes are adjusted correctly. You should be able to turn the drums with no friction from the shoes. If they are adjusted too close, they will lock before the front calipers get preasure.