hksnlper

Hi Every one, I recently bought a 1999 Chevy Express 3500 Cargo Van for our delivery business. I face a weird problem with the van. The left driver side rear brake locks up. Here is the issue while driving when you touch the brake the driver side rear brake locks up and some times its normal. I went through 4 mechanics and no one can figure out the problem. The van only has 79000 miles. The Brakes are new. Master Cylinder is Brand new, All rear cylinders are new. The drums are good. No one can figure out the problem. So far I spent $1183 in new Brakes, Parts, and Labor. I dont know what else to do and who to go to. Any one with any ideas. We already disconnected the ABS pump and tried and the brake still locks up so its not the abs. Any help will be appreciated or any one in Houston, TX area that you can recommend me to.

RacerX

I dont get it man. This car has ABS so the wheels should not be locking up at all. But all in all I dont see why anyone hasnt replaced the brake proportioning valve or the combination valve whichever this thing has. Clearly from this issue you have rear drum brakes. And I ll guess this setup is like my Cadillac where you have a BPV for the left wheel and the right wheel individually. On my Cadillac they are under the car in the brake line under the rear driver side door. They may be at the same place on this 3500, in front of the rear wheel well on the drivers side. That sounds like the only thing that could cause this dealie for you. And since I m not sure if you had this problem with the ABS connected, you might want to replace the ABS wheel sensors...it should be on this car since its OBD II. Try that

vantasy1

When you said in the Houston area, this guy came to mind. He has a weekly radio show.

http://www.texascardoctor.com/cardoctorshow.html

Skeeters Auto Service 12133 Old Huffmeister Rd. : Cypress, Texas 77429 281-469-1152

hksnlper

Ok Guys. Brake Proportional Valve was replaced including the Master Cylinder. My problem is only with Driver side rear wheel. When you touch the brake it locks up. IUts not with any other wheel. The Cylinder is new. Today we change all the springs, Brake Shoes and Bled the brake lines. Still the same issue. I also took it into the local Chevy dealer. They came back with an estimate of $1900 inlcuding replacement of drums, Brake shoes, Cylinder and ABS Pump. I seriously wanted to slap the service advisor when he started telling me all this Bull.... I just cant figure it out and cant handle it no more.

RacerX

The drums are good you say. BUT are they the same? What are the dimensions? If one drum is at maximum ID width and the other isnt the same, the drum with the smaller internal diameter width will lock up before the other one will because the shoes dont have to travel the same distance. For example, if your new shoes have to travel 25mm to meet the surface on the left side and 15mm on the right side because the drum surface is at max., then the right side will lock up until the left side can touch the drum. And the faster you go the worse it would be because the right side is in contact much longer than the left side and can only lock up or activate the ABS. But if the ABS doesnt come on then it means that your lock-up condition happens at speed below 35mph.

Other than this there should be no remaining parts in your car that you havent replaced. Nothing left but the brake line running to the rear. How long have you had this car? Was there 1 or 2 BPV? Does this car have separate brake lines for the left and right rear? Let me know. My Cadillac does. 2 BPVs. Hard to diagnose via computer but those were areas you should have looked at. Post pics of the inside of the drum if you can.

I m curious as to what the dumbasses at that Chevy store told you and how you responded to a tab of $1900? They saw brand new shoes and hardware and then "OK, let s sell it to him again"????????????

vantasy1

The Chevy dealer is the last place that I would go to. Check the rubber brake hose feeding the driver side rear brake, it maybe collapsing internally.

bartwilk

Hi so what did you finally end up doing.
I am having the same problem with a 1998 Chevy Express
we have changed pretty much everything you have changed and my right rear wheel locks up .
we have changed the drums from left to right and still the same right side locks up
HELP!!!!!!!!!!!

mel902

Had the same issue on my half-ton a few years back.Had it to three different shops and they could not pin point the issue.So i ended up taking it home and deciding it should not be that hard to figure out.So i took off the wheel ,drum and looked at it for a few minutes.Everything was new so there should be no problems.Then i noticed the end of the emergency cable end was right below the shoe and was binding so when i touched the brakes and the tire would lock up. I just bent it out of the way and never had the problem to happen again.

bartwilk

everything seems to be good there.
I have read somewhere that the shoes could be poor quality and could be causing the locking.

jerryr

C'mon guys...........Vantasy1 gave you the answer. Brake hose is collapsing internally. Classic problem causing this symptom. And dont buy the cheap ones ! My 99 Express had a pulling problem.....not as severe as locking up....but 3-4 shops did not diagnose correctly. Simple brake hose... fixed.