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View Full Version : no more shimmy!



brick8
02-17-2007, 10:05 PM
Finally had a warm spell here today (up in the twenties) so I was able to install the OP Parts rotors and mintex pad that I bought about a month ago. Only problem I had was removing the caliper holder bolts (the 19mm ones) because they were on too tight. Had to use about a two foot pipe on the end of the breaker bar to get them loose. The old rotors were down to about 20mm which could explain the terrible shimmy I had when braking.

The good news is the shimmy is totally gone. I was afraid I needed some new bushings, but the new rotors seem to have solved the problem. The bad news is the car now squeals like a stuck pig when stopping. Kind of surprised, because I coated the back of the pads with copper anti-seize, which had always worked for me in the past. Do you think the squeal will go away on its own? I noticed that there was some sort of plastic coating on the backs of the pads. Could this be the culprit?

MTV
02-17-2007, 10:56 PM
Congratulations! I too had a really bad case of the shimmy's under braking from around 55mph and up. And I opted for the OpParts rotors and Mintex pads combo as well. Totally removed the shimmy's and she feels brand new. Put to rest my apprehensions of having to replace the usual culprits on the front end suspension.

:D

bsell
02-18-2007, 02:49 AM
Finally had a warm spell here today (up in the twenties) so I was able to install the OP Parts rotors and mintex pad that I bought about a month ago. Only problem I had was removing the caliper holder bolts (the 19mm ones) because they were on too tight. Had to use about a two foot pipe on the end of the breaker bar to get them loose. The old rotors were down to about 20mm which could explain the terrible shimmy I had when braking.

The good news is the shimmy is totally gone. I was afraid I needed some new bushings, but the new rotors seem to have solved the problem. The bad news is the car now squeals like a stuck pig when stopping. Kind of surprised, because I coated the back of the pads with copper anti-seize, which had always worked for me in the past. Do you think the squeal will go away on its own? I noticed that there was some sort of plastic coating on the backs of the pads. Could this be the culprit?

There seems to be two schools of thought on stopping disc brake squeal; stick the pad to the caliper, or insulate the pads from the caliper.

I would say you tried the insulation method by using anti-seize between the pad and caliper. If the pad had some kind of material designed to 'stick' the pad to the caliper, your anti-seize could be in the way. So it might be worthwhile to wipe the anti-seize off and give it a go.

I can't remeber if the pads ride on spring clips or not. If they do, changing out the spring clips can help prevent the dreaded squeals.

Sometimes, resurfacing the rotors is the only thing that cures a squeal condition, and that might not last too long once the 'grind' gets ground off.

TC535i
02-18-2007, 01:28 PM
I've always had better luck with "sticking" the pad to the caliper. Usually the front pads have a three-spring clip that goes inside the piston... Make sure these are as far out as they'll go and still go into the piston, but you want them pressing out tightly. Might try bending them for a better fit.

I just use parts house pad adhesive spray, it's red in color. Line em up on a newspaper on the floor, and give the back a nice even spray. Well covered, but not TOO thick. Give it a few minutes to get tacky, and install. Works great.

bsell
02-19-2007, 02:56 AM
I've always had better luck with "sticking" the pad to the caliper. Usually the front pads have a three-spring clip that goes inside the piston... Make sure these are as far out as they'll go and still go into the piston, but you want them pressing out tightly. Might try bending them for a better fit.

So just like in other areas of life, 'tight' is good?;)

Brian

brick8
02-19-2007, 08:54 AM
Congratulations! I too had a really bad case of the shimmy's under braking from around 55mph and up. And I opted for the OpParts rotors and Mintex pads combo as well. Totally removed the shimmy's and she feels brand new. Put to rest my apprehensions of having to replace the usual culprits on the front end suspension.

:D
did your brakes squeal after putting the new pads and rotors on? I fear I might have messed things up by following the bedding in procedure that I found linked to this board.

MTV
02-19-2007, 11:19 AM
did your brakes squeal after putting the new pads and rotors on? I fear I might have messed things up by following the bedding in procedure that I found linked to this board.

I made sure to coat the new pads with anit-squeal lubricant but they still seem to squeal on and off. I plan to take a look at them this weekend after I replace the rear pads and rotors. Try and see what seems to cause it.

brick8
02-19-2007, 01:38 PM
I may try to do this tonight if I have time. The squeal is truly earsplitting--the loudest I have ever heard from breaks.

MTV
02-19-2007, 01:55 PM
I may try to do this tonight if I have time. The squeal is truly earsplitting--the loudest I have ever heard from breaks.

Let me know what you do and how it pans out. If it works I will give it a try.

:)

brick8
02-19-2007, 09:33 PM
It was a lot quieter on the way home tonight, so I think I'll give it a bit more time. Could be due to our heat wave (42 degrees!).

RallyD
02-19-2007, 10:07 PM
I may try to do this tonight if I have time. The squeal is truly earsplitting--the loudest I have ever heard from breaks.
stop taking so many breaks
and fix your brakes, :D

aston_jag_tech
02-20-2007, 12:19 AM
Squeal is usually suspect of the brake components vibrating and has been an issue for the manufacturers of the brake pads. NVH baby.
Fully lube all components on the caliper that slide, rub, touch, bevel your pads if not already, a new spring clip isnt a bad investment but I never have.
Also if your pads are performance or longevity pads, that determines squeal amount.
Like Brembos....
We use a combo of a product distributed by MOC chemicals that is soaked into the brake pad friction surface to help bed in the pads to rotor. Then, the use of Brembo brake lube(Love it) Not too much lube though...attracts dust very quickly.

But the question...When do they squeal?? What temp, day/night, hard/light application..??