Idoktr

When installing new brake pads (metal masters) on the front of my 1991 C2, do I need to use copper paste to prevent future squeeling? If so, where and how much paste to use? Also should I leave the old "mushrooms" in place or remove them to reduce brake squeel?

Thanks,
Stewart

PS Still looking for a hand in replacing the pads in Metrowest Boston

JasonAndreas

After you separate the brakes pads from the mushrooms you should be able to tell if replacing the pads is going to make any difference (unlikely). If you have difficulty pulling the pad than you know the spring plates are the problem and not the choice of pad. Your mechanic recommending caliper replacement is another hint that the plates are the problem.



Instead of copper paste try something like Permatex Brake Quiet or the Loctite Disk Brake Quiet stick. The Permatex usually comes in a spray container and you apply either product to the back of the pads.



The mushrooms are not reuseable. They will still sorta stick to the pads but not really.

I might have to stop by EPE in Natick (for machineshop work) this week but I'm waiting to here back from Jerry (I live 3 hours away), if so I can help.

dfinnegan

Can someone please explain what the "mushrooms" are?

Perhaps point them out in this pic?

Thanks,
Dave

Eric Kessel

Parts #20 and 21 (they are different diameters). The "mushroom" spring end fits in the piston, and the flat side has an adhesive to stick to the brake pad.

mojorizing

here's a photo of the other side of one depicted in the above parts diagram

Idoktr

upon advise of a fellow rennlister. where can I put the paste,as I am not replacing the mushrooms, just the front pads.

S

Idoktr

Just replace the spring plates?

JasonAndreas

On the backside of the pads where the pistons push against it.

The thing is you said your mechanic (who are using?) already tried replacing the pads, etc. and recommended replacing the calipers. If that's the case and you need to heavily file the sides of new pads to get them to fit then your problem is probably related to the plates. You can check pretty easily by trying to remove your existing pads. IF you have a lot of difficulty pulling them upward then you've found the reason for the squeak.

Idoktr

at EPE....I just don't have the $$$$$$$$ to replace the whole system.

JasonAndreas

There is no reason to replace the whole system or even a single caliper. When you go to install your new pads take a look at the spring plates and see if one or both are bending away from the caliper or if you have to file away a good portion of the new pads to get them to fit. At worst you're out $13-16USD for a new plate as there is not a whole lot that would go wrong with your calipers and require a total replacement.