Rear Bias Valve Causing Hot Brakes?

[ckinart]

Hey all,

I recently discovered that my rear right brakes were in dire need of replacement (were pretty much disintegrated and showing obvious signs of heat damage) and the rear left weren't so great either. Assuming that the rear right wear was due to a seized caliper, I ended up having the calipers, rotors, pads and flex lines replaced on both sides (the left side was pretty tired as well).

Shortly after that, I noticed that my rear right wheel was occasionally very hot after some city driving (not aggressive). I replaced the e-brake cable on the right, but that didn't help. I took the car back to the shop that did the brakes originally, and they replaced the rear right caliper again saying it was "hanging up." Well, after all of this, I still find the rear right wheel to be very hot after city driving (not after every trip, but more often than not).

So, since the caliper has been replaced twice and the problem persists, I think the caliper can be ruled out. I've heard of the possibility of the caliper bracket being warped causing the slider pins to hang up, but I'm fairly certain this isn't the case as the slider pins are new and well greased, and slide freely. So the question is, can the rear brake bias valve cause this condition?

I plan to have the valve removed and just join the lines with unions (I have 4 wheel ABS and don't want to install a new valve if it could just cause me more problems in the future), but I want to be sure that I'm not wasting my time.

Any comments? If anyone can confirm that a bias valve can cause one side to stick and/or run hot, can you please explain?

Thanx in advance!!

<small>[ August 19, 2003, 06:51 PM: Message edited by: ckinart ]</small>

 

[Revere sho]

im thinking thats my problem to i would love the help i replaced my left rear caliper twice and im about to change the right rear again cause its running extremly hot. but the pads are new and the caliper wasn't frozen. if anyone can help that would be great thanx

corey

 

[Ishodu]

Sounds like the rubber hoses have collapsed at the mounting point at the strut and are not letting the fluid return to tank. You may want to replace these hoses not very hard job. You can also try to bleed them and see what kind of flow you can get out of that side compared to the other side of the car.

 

[ckinart]

Ishodu:
Sounds like the rubber hoses have collapsed at the mounting point at the strut and are not letting the fluid return to tank. You may want to replace these hoses not very hard job. You can also try to bleed them and see what kind of flow you can get out of that side compared to the other side of the car.

Thanx for the reply Marcel! The rubber hoses have been replaced on both sides so I don't think that they should be a problem. I guess I'll try bleeding both sides to compare the flow/pressure.

As for my original question, can anyone confirm that the rear brake bias valve could cause one side to run very hot and not the other?

 

[Yamaha V6]

I just did the rear bias plugs on mine, with the Earl's lines. I was told NOT to use the stock mounting point on the strut for the Earl's lines - it can kink the ss braided line. I straightened them out, ran them behind the strut as recommended to me, and everything came out much better - full brakes all around instead of just the rears to a certain point before the fronts would kick in. I still am waiting for the 11.6" replacement hardware to come in, after busting a caliper slider pin. BTW, I'd suspect either one line only is kinked, or the slider pin may be frozen on one side, perhaps.

Best of luck!

 

[ckinart]

Yamaha V6:
I just did the rear bias plugs on mine, with the Earl's lines.

Thanx for the info! Although I've heard of them, I'm not familiar with rear bias plugs. Where do they go? Would removing the bias valve entirely have any different effect?

Yamaha V6:
BTW, I'd suspect either one line only is kinked, or the slider pin may be frozen on one side, perhaps.

Well, I suppose it's possible that the steel brake line could be kinked somewhere between the bias valve and the flex line, but since the flex lines and calipers are new (and the pins are well greased), I don't think that either of those issues apply in my case.

Unfortunately, I haven't been able to determine whether or not the bias valve itself can cause one side to run hot and not the other

Thanx again!

 

[Yamaha V6]

No, you misunderstood me.

Earl's stainless steel braided flexible brake lines, from the hardline on the chassis to the caliper. The design is such that if you use the stock strut mounting screw location, you can potentially kink the flex line (not the existing chassis hardline from the distribution block in the rear to where the flexible braided line starts).

The other thing to check is your e-brake cable, make sure it's not frayed & hanging up.

 

[Mike Kopstain]

Have you ruled out a wheel bearing? A bad wheel bearing will heat that wheel up nice and hot.

 

[ckinart]

Mikeys_Taurus:
Have you ruled out a wheel bearing? A bad wheel bearing will heat that wheel up nice and hot.

I'm fairly certain it's brakes. Some days when I feel the rear right wheel after some city driving, it's at a normal temperature (only slightly warm). On others, the rear right gets very hot (the left is always fine). On a few occasions, the problem has been so bad that the rear right brakes are basically stuck on and you can hear the creaking sound of them binding up when you come to a stop or pull away Needless to say, this problem needs to be fixed ASAP to prevent any serious damage to the pads/rotors or worse.

As I've said, with new pads, rotor, caliper (twice) flex lines and e-brake cable, I'm running out of suspects. I plan to have the bias valve cut out tomorrow, but I'm trying to confirm that this is a legitimate attempt to fix the problem.

Thanx for the suggestion though!

 

[SHOZ123]

Might also be an e-brake cable. You can temporarily remove the cable from the clip on the caliper that holds it and see if that makes a change.

 

[ckinart]

SHOZ123:
Might also be an e-brake cable. You can temporarily remove the cable from the clip on the caliper that holds it and see if that makes a change.

Nope. Brand new e-brake cable which has been double and triple checked for proper operation.

Thanx though! thumb

 

[JaySHOguy]

In essence, couldn't you get the Brake Bias valve plugs and use them instead of removing it altogether? You would be allowing full fluid flow through it. Or, maybe have it removed and blow some compressed air through it. You could have a slight blockage, possibly?

 

[ckinart]

JaySHOguy:
In essence, couldn't you get the Brake Bias valve plugs and use them instead of removing it altogether? You would be allowing full fluid flow through it. Or, maybe have it removed and blow some compressed air through it. You could have a slight blockage, possibly?

Well, as I mentioned above, I'm not familiar with bias plugs (although I've heard of them here and there), so I don't know where they go, and therefore what they do. Could you explain?

Thanx!

 

[Yamaha V6]

Jay, the Bias Plugs DO replace the valves completely. You unscrew the 2 valves out of the rear distribution block & screw in the Bias Plugs...done. You then have full rear brakes all the time, which will stop you faster potentially, but also will generate more heat, and wear the pads & rotors faster.

 

[Rob94]

I am having a similar problem, except my "hot wheel" jumps from left to right whenever it feels like it. Whenever you figure out what is causing your problem, I'd be quite happy to hear about it.

 

[Xs SHO 1]

Yamaha V6:
Jay, the Bias Plugs DO replace the valves completely. You unscrew the 2 valves out of the rear distribution block & screw in the Bias Plugs...done. You then have full rear brakes all the time, which will stop you faster potentially, but also will generate more heat, and wear the pads & rotors faster.

how much fluid did u lose when u installed the bias plugs? did u have to use teflon tape on the threads of the plug or the teflon tape is not needed?

 

[Yamaha V6]

Not a lot of fluid at all. However, bleed the brakes very well after. You don't use tape, they come with rubber o-rings. The hardest part was removing the bias lever.

 

[SHO EET 1]

I am having the exact same problem. I stopped using the E-brake which didn't help. The right rear caliper has been replaced twice. New pads, lines are ok. When the car is cold no problems, after some time spent driving around town the rear brake seems to heat up and start chirping. The rotor is rubbing on the pads.

I have worn out suspension so I am wondering if I replace the springs and struts will the chirping go away?

 

[Shuey]

anyone know the thread pitch on these bias plugs?

 

[JaySHOguy]

Yamaha V6:
Jay, the Bias Plugs DO replace the valves completely. You unscrew the 2 valves out of the rear distribution block & screw in the Bias Plugs...done. You then have full rear brakes all the time, which will stop you faster potentially, but also will generate more heat, and wear the pads & rotors faster.

That is what I was getting at. The guy was talking about removing the entire valve assembly. Instead, he could just install the plugs and that way he wouldn't have to mess with the brake lines themselves.