Brake Pad Shims

[stumped]

About 15K miles ago I replaced the front & rear brake pads with aftermarket ones. The parts store did not have the anti-squeal shims so I reused the original. They were not in the best condition but they were intact.

The other day I heard a rubbing/scraping noise from my right rear. I pulled the wheel & one of the outer shims must have deteriorated enough & one edge dropped down & is rubbing against the rotor hub.

Are these shims really needed? Are they there strictly for anti-squeal purposes or are they needed for proper brake performance? And why the heck do they use 2 shims? If they were critical I would think aftermarket pad suppliers would also offer the shims. I never had a car that used shims & never had a brake squeal problem.

Should I get some OEM Toyota shims or just remove the offending broken one?

['88 All-Trac]

What sort of pads did you install? A lot of pads these days don't require shims or even anti-squeal grease these days. Typically, if a set of pads needs shims it will come with them- at least, in my experience they do. I only use ceramic pads these days and those specifically say not to use shims or grease on the paper inside the box... Haven't had squealing brakes since I talked the rest of the family into letting me install ceramic pads on their cars as well.

[stumped]

I installed some basic pads from Advance Auto, part # WREVR 5752388. I don't put many miles on the car so I figured these would last quite some time. In fact these were installed over 3 years ago but have only 13K miles on them.

IIRC the pads came with the wear sensor clips, but I'm not sure about any anti-squeal compound. But since I re-used the OEM shims I would not have used any compound anyway.

Either the aftermarket companies think that their pads do not require shims or they presume you will re-use the factory ones. At this point I'll just remove the broken shim which appears to be the solid metal outer one.

['88 All-Trac]

Some of them simply have the shim sort of built into the pad. Materials have come a long way in the 20 years since our rigs were designed and built.

I installed ceramic pads with no anti-squeal grease or shims on all four corners of the 2wd and it has no squeaks or squeals 3k later. As I recall, the Advance Auto pads need the grease.

I don't see why so many people insist on the shims- maybe it's my young age? I don't know. I simply follow the directions on the box and have quiet brakes. My brother bought some basic pads from O'Reilly Auto and those did require shims- they came with them. This was about a year ago.

I often apply anti-squeal compound to every moving part of the caliper that doesn't come into contact with the pads- as well as on the bolts/pins.

Edit: I have noticed that if the pad springs are missing, the brakes will squeal. Rockauto has the springs for sale for some $1.50/pair. Good deal to quiet some squealing. My brother's Celica lost a spring in the rear and the disc has warped; I'm not sure if these are related but I could see a dragging pad being a bad deal.

[stumped]

I did the front brakes a few weeks after the rears & also used Advance Auto pads and re-used the shims. These too came with the clip-on wear sensors and also the springs.

I never come across shims & never had a squealing problem with any of my cars. I guess I'll just take out the shim which appears to be the solid metal one.

FWIW I did install ceramic pads on my other car.

[Doctor J]

I am using black RTV on the outer pad

[Mike Gerber]

"At this point I'll just remove the broken shim which appears to be the solid metal outer one."

You could try that or just spray some Disc Brake Quiet (I prefer the Permatex brand but any brand should work fine) on the back of the pads while they are removed from the caliper. Then let it set up about 10 minutes and then reinstall them. It might save you the trouble of having to remove everything again. A can of the spray runs about $5-$6 and will probably last you about 25 years.

Most brake noises are caused by the pads vibrating in the caliper. The spray disc brake quiets are tacky substances that cause the pads to stick to the caliper and caliper piston to eliminate the vibration.

Just my 2 cents.

Mike