Cobra454x

Hello everybody! I am new to this forum, but very much am a bowtie boy. I currently own a slightly customized 1986 C-10 Silverado, and I'm having alot of trouble with the brakes lately. for the past few months, every time I hit the brakes, the truck would pull to the right for just a split second and then stop normally. This baffled me a bit, but since i needed to do the brakes on it anyway, I got new rotors, calipers, and pads for it and installed them. After wich time I took the truck out for a rest run and what do ya know...the truck is still doing the same freakin' thing. Annoyed, but not entirely dismayed, I continued driving the truck as I normally would have with this pulling problem. Now I just took the truck out once again for a little stoll since its been sitting for a couple weeks, and now the 1 month old drivers side caliper is hanging all the time, so the truck is pulling to the left while driving down the road, and the freaking thing will STILL pull to the left for a split second when you hit the brakes to stop. I am very confused with this. I've never run into this problem before. I've confirmed that it is not the new caliper, because i took the wheel off and released the fluid pressure off the caliper and it releases the brakes. I have also confirmed that it is not the master cylinder, because I jacked the front of the truck up and checked both wheels....they both roll fine....then you hit the brakes and release them, the passengers side rolls fine, but the drivers side stays locked. If it were the master cylinder, both front brakes would stay locked. I am really baffled at this thing, and I'm looking for some outside information. I've heard that what it's doing could possibly be linked to the porportioning valve. I have also heard that you can "gut" that valve. I know absolutely nothing about these things and am looking to you guys to see if any of you have had this problem and if this is the solution...Thanks in advance for any input guys. Looking forward to hearing from you....

OH!!!! yea, incase this helps or rules anything out....the truck is factory equipped with heavy duty brakes all around. And no, the truck is NOT hydra-boost. Hope this helps...

golfer

Not necessarily ... the brake's hydraulics are plumbed in a tandem configuration. Meaning.... the front left brake is plumbed with the rear right brake.... thefront rightis plumbed with the rear left.
That's why when bleeding the brakes you start with a rear wheel then do the opposite front ... in a X fashion.


The role of the proportioning valve regulates the fluid pressure between the front and rear. The front brakes receive more fluid pressure proportional to the rear brakes ... 70% / 30% for example.

Not sure what you mean by this but if you are talking abouteliminating it ... bad idea.


I had a similar problem with my 86 C20 though the problem didn't move sides. In my case I found the rubber flex lines to be the problem.
What happened was the rubber had become too soft and when applying the brakes the hose would balloon then collapse when the brakes were released. The side this was happening wouldn't receive enough pressure at that caliper and the other side was braking more pulling to that side. Then when the hose would collapse would hold pressure on the caliper not allowing it to release.
Now this may not be the situation in your case... but worth mentioning.

If you're 100% sure the the calipers are good and the slide pin is clean and lubed.... then check the flex hoses ,the rear brakes , possibly flush the brake fluid.

Just some thoughts.

novaracer

It seems to me it is likely be a rubber brake line problem. If there was a bad control arm bushing on that side it could allow the control arm to move and steer the car one direction or another for a short time until the driver "corrected". You'd likely hear a clunk when applying the brakes or turning though.

bigbodychevrolet

If you havent resolved the problem yet. Here is something I bet you haven't thought of. Drive the truck in reverse and see if it pulls the opposite way. If it does then the pulling issue is in the steering linkage somewhere. Possibly a tie rod a little loose. Lift the front wheels and grab theside at9 and 3 oclock positon and moveback and forth and watch and see what is moving where it could be loose.Maybe better with to people. If nothing else has helping in the brake sys then give this a try.