Brake Shims Breaking

They rust out?

I always put a thin coat of anti-seize, at all the points of contact, pad back, to shim, to caliper. They last a long time, little clips finally start to rust out.

 

Try to have the caliper disassembled and carefully inspect it and the hardware. Shouldn’t be making that unusual noise...

AutoZone Duralast DGC990 have a nitrile shim on top of a steel one....

 

I can't say this is normal as I have not experienced this issue. My 2004 logged 231K miles before I sold it, and the front brake pads were replaced once during that ownership. My 2007 currently is at 130K miles and I have not serviced the brakes yet.

What brand are you buying? If you are having repeated issues I would suggest you try sourcing from a Toyota dealer parts department.

 

I'd like to understand what you mean by "keep breaking", as I have not experienced any problems with the shims.

The brand I use is Toyota as I figure I will only do them once in my ownership. It is not normal for them to break, in my experience.

 

@alex rodriguez is it shims or pads?

 

Those items are not the anti-squeal shims, they are a set caliper pin dust boots and the brake pad support clips that clip into the top and bottom of the caliper bracket. So, are you saying the support clips are breaking?

 

Yeah that's a good first step, could be inferior aftermarket, ill-fitting or something.

 

So, how much have you spent on all those clips from those places?

They are actually called "Fitting Kit, Disc". Part# 04947-47010. They are the brackets only. The dust boots are part of the "Cylinder Kit, Fr Disc" part# 04478-47070

I'm still having a hard time trying to visualise how they break.

Do you have a picture of a broken one?

 

Maybe the aftermarket brake shoes aren't fitting??

 

NO surprises if the aftermarket supplies are of poor quality/construction/materials, and fit poorly.

Are you doing the brake job correctly? Brake grease onto shims, and contact points of pad support plate. Lubricating the caliper slide pin. Check for minimum rotor thickness and runout. Check pad thickness.

 

The Toyota pad support plates come with a dry, Teflon-like coating, and no recommendation in the manual to apply grease (which would tend to be a grit magnet).

The dry lube coating does not last forever.

 

It took me 3 hours to figure out the FU means flange up..haha I just installed my second set of shims on the 08 Prius. First time it just didn't look right, and sure enough when I came back to lube pins I found that I had sheared off an "ear" on the black shim on the inner side. That's because I thought it went on like the others with the little fingers grasping the pad. But on part 04945-20210 Toyota Disc Brake Pad Shims the little "ears" on the black shim on inner pad go up around the silver shim that is placed over it. In this picture I have it on upside down. If I flipped it over then it would fit beautifully under the silver shim with ears pointing up away from the pad vs. all others you see in diagrams. This pic is WRONG way. I'll try to get one of the right after the rain stops. Note how the little "ear" is wrapped around the upper part of pad body that fits in the slide? Not only does that ear get bent or torn off and prevent the shim from floating properly, but it also has the other parts poking out over the pad and hits the caliper frame impeding movement.



This is how the black fits together with the silver correctly on the inner pad shim on 08 gen 2...OR please correct me if wrong, but there is no option I can find.



Of course then you flip it over and the silver latches on to the pad trapping the little black piece underneath in all the right places.. Notice the black tabs pointing UP away from the pad but locking into the silver shim.