rr-racing Wilwood issues

[larryt]

I picked up the Wilwood Stage IV calipers along with the rear caliper set up for the BRZ. This included new rotors. I have a few posts regarding pads and squeaking below, but I am starting to think I have a caliper issue to deal with first. These things are literally locked up and I think that led to glazing of the pads (thus the intense squealing/squeaking).

I am trying to figure out why these may have locked up, but also find out if anyone else has had any issues with these calipers?

Some basic facts:

- We have driven about 2000 miles since install
- We replaced the brake lines with new steel lines
- We have removed the calipers from the car to rule out anything from the lines
to the M/C as causing the issue.
-The calipers are on the bench and the pistons will only move if applying
pressure (air in this case) or using a mechanical spreader. They will not budge
no matter how much force I apply manually.
-Before removing the calipers it was clear that the drag was much greater than
under normal conditions.

I think it is fair to say the seals/o-rings are the problem, but why would they have this sort of failure so quickly? Am I going to continue to have this problem? Or should I be thinking that it is something else.

If anyone else has experienced this please let me know and how or if you were able to resolve the issue.

I contacted rr-racing, but they could only offer to look at them if I shipped them back without much insight as to possible causes. That may be the best thing to do, but if I am going to have recurring problems I would rather find out sooner than later so I can move on having experienced an expensive lesson without investing too much more time.

Thanks.

[NoHaveMSG]

Have you pulled the pads and taken a look at the dust boots to see if they got melted?

Wilwood uses square o-rings in most of their calipers. The square design rocks up on edge and helps retract the piston when you let off the brakes. I have seen issues with the square o-ring, or the grove in the caliper for the o-ring be out of spec. This would cause the edge of the o-ring to shear and wedge itself in the piston and lock it up. I have also seen contaminant cause the o-ring to swell, or people use knock off o-rings that are off the wrong material that would swell with standard brake fluid. They should be EPDM at minimum.

[Lynxis]

Originally Posted by NoHaveMSG

Have you pulled the pads and taken a look at the dust boots to see if they got melted?

Unless something has changed in newer versions of this kit, the Wilwoods don't have dust boots.

For the OP, I'm not sure if this is your problem but I thought I'd make a point of mentioning it. I had the RR Racing Sport Performance kit and had some funny problems in the early days of using it. In particular, the pads didn't quite fit into the caliper properly and I was just forcing the pads in with a mallet. Bad idea because that was causing me to drag brake pads as they wouldn't release from their position against the rotors properly.

The solution was to just sand the paint off the edges of the backing plate that contact the caliper, and then they would slide in easily and my problems went away.

[NoHaveMSG]

Originally Posted by Lynxis

Unless something has changed in newer versions of this kit, the Wilwoods don't have dust boots.

For the OP, I'm not sure if this is your problem but I thought I'd make a point of mentioning it. I had the RR Racing Sport Performance kit and had some funny problems in the early days of using it. In particular, the pads didn't quite fit into the caliper properly and I was just forcing the pads in with a mallet. Bad idea because that was causing me to drag brake pads as they wouldn't release from their position against the rotors properly.

The solution was to just sand the paint off the edges of the backing plate that contact the caliper, and then they would slide in easily and my problems went away.

Yeah I could be wrong there. I am not well versed in Wilwood even though I am a dealer for them.