Wilwood rear disc brakes

[novadude66]

I'm having a hard time keeping my Wilwood discs on my FED released, has a 2lb residual valve and dynalite calipers. Does anyone have any suggestions?? Pulling my hair out!!!

[BK]

If it happens when its cold make sure the piston in the master cylinder is returning all the way back to the snap ring every time? If it happens when its warm after a run you could have air trapped in a caliper.

[Dolmetsch]

After a local racer crashed his RED twice with pad failure with his lockhearts which failed (lost a puck both times about two years apart)his wife forbid him repairing it and he sold the car to a friend. We had two other at our local track have similar failures. I do not like the set up and so did the math finding that a set of normal caliphers from a minim van had more then sufficient ability to stop the car and were a much better made piece incapable of that failure so I made asset of adapter plates to replace the airhearts, machined up two  spacers to pop in the pistons to bring the calipher and pad in proper contact with the hats already on the car. I used a ceramic hi quality pad available at  any parts store in North America. That was over 10 years ago and the car is still run regularly and has been tagged with no issues two times. He reports braking is not an issue and in fact since the change I don't believe he has ever used his laundry although maybe I just aren't always there. Pad life has been good . In fact I think they are still the ones I installed. That is how we solved a bad problem on one car. Why do you have a resid valve on disc brakes? Unless the master is along way below the caliphers (which is near impossible  on a fed or RED) a resid valve should not be installed and even then it is a bandaid at best. Resids are for drums. And they are a very misunderstood device.
don

[dusterdave173]

I seem to be having similar issues--have new Wilwoods on rear , 2 lb valve, and after six runs rotors are purple--brakes work great, stop like a Caddy but....I have really looked it over and they do not seem to have any more drag than other disc setups but they don't seem to be releasing totally--hard to tell when turning everything as you can imagine--my rod is all the way out to snap ring I am sure--have hard pedal with very little travel--if I did not look at the rotors I would never know--no stinking or symptoms  that really stand out--I get a little smell after a stop in the 1/8th from 122 MPH but that would seem normal right? Car rolls around shop fine so WTH? If I take the valve out what could be worse thing? Little more pedal travel??

[wideopen231]

Seems there should be spring loaded setup to totally disengage pads. Always thought their had to be some frictional loss there. If that simple I guess somebody would have already came out with it.

[RacinJacin]

Wilwood recommends a 2lb residual valve be used when the m/c is at or below the height of the calipers. Wilwood recommended it - so that's how I did mine - no problems yet. I run the dynalite calipers and their M/C with a lightweight pedal.

AS for some of those "puck" style brakes. A fellow I knew ran them and spit a puck out right before a big race - it was the style where a small band of aluminum ring in the caliper is what kept the puck in place. That narrow band sheared off and out went the puck. As a band aid I c'bored the caliper and made a steel sleeve to press into the caliper - 1/2 in 1/2 out. Now you had to either shear off a WHOLE bunch of aluminum or that steel ring in half. Even so I told him to throw those calipers away first chance he got. I would NEVER run that style of brake caliper.

[ricci32]

In the mastercylinder its self there is a built in residual valve on the end of the piston there is a cup with a circular group of holes and a rubber flap over the holes I have been told by in the past on my dirt modified to remove the rubber flap especially if you are usinig residual valves. I have never had to use residule valves.   

[ricci32]

The problem i was having was a draging of the brakes and brake fade and loss.

[masracingtd1167]

I use the Wilwood brakes on mine without any check valve unless it is in the master . It is mounted below the callipers . The only problem that I have had is the transfer of metal from the pad to the rotor but they never drag .

[dreracecar]

Airhearts had puck retractors in the caliper pistons--- nothing but a pain

[RacinJacin]

I would think that the truer your rotors run the less effect you would see when eliminating the RPV - speaking disc brakes.

I would imagine that Wilwood's advice stems from a liability perspective. Reccomending them must put them at a lower state of liability than not.

I can also imagine situations that they may not be necessary - if you aren't experiencing excessive pedal travel and the vibrations aren't causing issues - maybe they are not needed.

Novadude, how much free play do you have on the rod?

[novadude66]

Great to hear all the responses!!! The rod probably has 1/4 inch of play in it, and it appears that the MC is returning to where it should. I believe I'm gonna remove the residual valve and try that (very carefully of course.) My MC is not very far below the calipers at all.

[masracingtd1167]

I thought of one more thing . How old are the calipers ? I did have a problem once and I rebuilt them and they were fine after that . S+W sells kits for them and they are very easy to do . Bill

[novadude66]

They are a couple years old, I'm gonna put a master on it cause they are cheap. Gonna leave the residual valve off of it and see what it does.

[novadude66]

Got the master on it minus the valve, pedal seems pretty good but wont know until i can test it out. Remote resovoir sits quite a bit higher than the calipers dont know if that makes a difference or not but we will see....