I have an 87 camaro that I just recently put a BW disc brake rear end in. I have a grinding noise in the front after about 10 minutes of driving. The caliperis and hoses in the front are only 1-2yrs old. In an attempt to fix the noise I replaces the wheel bearings and durting that process I re-set the calipers with a c-clamp. They seemed to reset easily and smoothly. I was driving today, and whenm I got where I was going, I dipped my fingers in a puddle and touched the rotor to see if it was warm it sizzled, so I'm sure that the brakes are never fully releasing. When I did the rear I replaced the prop valve with a junkyard one because I stripped some threads in the old one. (I also Modified it like I hear alot of you guys do and the rears work awesome).
My question is, do you guys think that the calipers are seized, the prop is bad, or the hoses need replaced again? I just finished doing all of the suspension during which the calipers hung from cloths hangers for about two weeks and the hoses may have been damaged during that. I'm putting the car away til I get this issue resolved and there is limit time left to drive this year so hurry and give me ideas please. If the prop is to be blamed, I may try to rebuild it using the parts from the old one, is this possible? How do I get the internals out of there for the fronts? I tried geting the guts out of the front brake portion of the prop valve once already and was unsuccessful.
Thanks for the help
Nate

 

if you still have the stock rubber flex hoses on the front, its quite possible that they are collapsing and holding the calipers on.
However, after driving, the rotors will be warm, thats normal.

As for gutting the valve, i have no idea. People always say they gutted the valve, but when i wen tot do it, i could not find a plug to cap the end off with, and there is a piston that is between the front and the back of the block and there is no mention of how to deal with it.

I gutted my prop block, cut the section off for the rear brakes, and had a buddy weld all the extra holes shut, making just a junction for the front brakes, then plumbed in a adjustable valve for the rears independent of the block. Works great, but requires doing some tubing bending, flaring and some oddball fittings.

 

I got the valve gutted and I will swap insides. I'm also going to put an order in for front SS braided hoses. If that's not the problem, you guys got any other ideas?

 

I am having the same problem with my front driver side brakes. I just put a new stock caliper in and it is still seizing up. Why would you need to gut the valve? I am thinking about changing the brake line to the ss braided line i hope that is going to fix my problem but any tips or past experiences will be greatly appreciated.

 

The hose is likely the culprit. Swap both (or all) with new, rubber or SS. You don't need to gut the valve.

JamesC

 

More than likely the brake hose. Remove the cap from the master cylinder up top, then disconnect the brake hose from the caliper, and see if the fluid starts trickling out. If it doesn't, put the cap back on the master cylinder, then have a buddy slowly depress the brake pedal all the way down. If it's only trickling now (but not gushing), your brake hose is collapsed, and is either acting like a check valve, or a restrictor. I have an extra brake hose if you want, although they're cheap enough at the parts store. By the way, for future reference, never c-clamp a caliper's piston while it's still connected to the master cylinder line without allowing fluid to bleed through the bleeder, as this will cause binding, and the same exact problem later on down the road, or sometimes even immediately after....

 

What do you mean by binding? I'm redoing the PV because I used a junkyard one after I stripped the threads in my old one. I just want to make sure that that is not the problem since it was installed between the time when brakes worked fine and brake screwed up. For the record, I did not c-clamp the caliper until after I was having issues. Why woul;d it cause a problem? I thought that fluid was supposed to be able to flow back to the master unobstructed.

 

C-clamping the caliper is fine, it's how you do it though in which will determine if it will accidentally bind up (seize). To make a clear path for the piston to ease its way back into the caliper, you'll want to loosen the bleeder screw, and/or remove the cap from the master cylinder, this way the piston will slide itself back smoothly. If you keep the bleeder fastened, and the master cylinder cap on, your creating resistance for the piston, and it will bind itself into the caliper if it's forced too hard, not to mention kick back whatever rust has accumulated along the way into the brake hose....

 

I can't remember if I removed the master cylinder cap or not but the piston didn't put up much resistance to being reset. It was barely more resistance than I wanted to push by hand, so there is little chance that I caused a bind.

 

i replaced the MC and the brakelines. The MC was definately bad, leaking fluid from the resevoir seal bad. I replaced the brake lines with SS braided lines. HUGE Difference. the brakes don't stop the car much quicker, but the pedal is way stiffer. I can move it about 1/2 inch then solid as a rock. I used to be able to press the pedal to the floor if I wanted. Definately do this upgrade. stock brake hoses are junk.