Pad Knockback Issue

[Sleeper68]

I have the same problem with my rear Wilwood brakes. I tried 10# RPV for a short period before removing them. I felt that the drag was noticeable and the rear brakes were unable to effectively shed heat.

After a series of braking test I did a "cool down" period and monitored the temps. The front brakes were substantially cooler than the rear. My theory is the RPV drag was causing the increased temperature and I removed them. I have played with trying to tighten my bearing lash on my semi-float axle, which has helped a hair...but not a lot.

I've just chosen to live with it and check-up the brakes after reasonable turns. It's habit now.

That sounds like pretty significant drag. I think I'm going to try a call with Wilwood again once I verify the silder travel. The travel is a bit tight on the inboard side, but performing a free body diagram analysis of the caliper body didn;t net an explanation for any piston compression.

You say you were able to significantly reduce axle float in your housing and you're still experiencing a lot pad knockback. This is a little concerning because to me it means the movement of the rotor is coming from the axle's deflection... Much more difficult to address. Maybe it is full floater time.

I'm not an expert on caliper piston seal design, but as far as I know, they are all square in profile, and the design of the seal groove has more of an impact on behavior than the seal itself. Here's a white paper on the topic if you're interested in more detail (not my paper btw, just stumbled on it looking for figures to illustrate what I'm talking about): http://www.simulia.com/download/solu...c03_delphi.pdf

Very interesting read. You use alot of engineering rhetoric. Are you by chance one?

My hope would be that Wilwood has the seal/groove design thing down. It is a pretty critical component of the caliper's design.