Outer Limits 4x4 Board

OK, finally got around to doing the brakes (Long story why I haven't done them yet)

First found I didn't need to do them anyway, there was heaps of pad left, but since I went to the expense of buying some very good quality 4wd specific pads, thought I might as well put them on anyway.

Paid very careful attention to exactly how they came off, and how the shims were arranged, and put them back together exactly the same way, but whatever I've done wrong they now "sing" as I drive along.

I even carefully followed the "bedding in" instructions that came with the pads. But "sing" they do. It's a very high pitched sound (a bit like it would make if a shim was rubbing on the rotor or something, but that doesn't appear to be the case).

The only thing that's different that I can see is the old pads have some sort of papery gasketty type sheet stuck or glued to them which is impossible to remove to put on the new pads. Nothing like that came with the pads I bought, so am I meant to try and locate some of these paper doohickeys, or is that not likely to be the cause?

On the plus side, she sure stops better now
(And yes, I am joking, I'm hardly going to keep driving it with something rubbing, the heat generated would be dangerous.)

Is it "singing" on both sides? Check that the backing plates are not rubbing on the disc. If they are just lever them back a bit.

Not certain, the singing seems to be coming from the passenger's side only, but not 100% certain of that.

Ezookiel wrote:Not certain, the singing seems to be coming from the passenger's side only, but not 100% certain of that.

I guess a singing brake pad is better than a whining "handbrake"

May sound obvious, but did you make sure the piston moved freely, and that the caliper pins had some grease on them? Sounds like the caliper piston or caliper assembly may be sticking just enough to leave the pad gently touching the disc. Could be a bit cockeyed/jammed on one pin too.

Does the singing stop with gentle application of the brakes?

do they have a wear indicator that is perhaps sensitive to fitting, ie, must be fitted a certain way??

PS what shims are u refering to - our Disco don't have shims. We did have a noise with new pads recently, thought it was the diff but was just a stone or something stuck in the pad. Try reversing and applying the brakes hard to clear out any rubbish.

There may be a number of reasons why your brakes are now squealing. The few that spring to mind are that some harder compound pads will almost always squeal no matter what you do. Secondly if the rotor has any abnormal wear, the previous pads will have shaped themself to the grooves of the disc. Fitting new pads to buggered rotors will cause a squeal. The papery stuff you are talking about may be an anti squeal product. You can buy a tube of anti squeal compound which is smeared over the back of the pad to stop it vibrating on the piston.

As others have asked. Did the pistons(s) move freely when changing the pad? have you tried rubbing some fine grit sandpaper over the rotor? checked for high spots? ( these will be shiny )

If it is mainly happening while you are driving along without your foot on the brake you may have a lazy piston.

Well, thanks for the suggestions, but whatever it was it was solved by pulling them out and putting them back in.
The shims I was referring to are the very thin metal plates that went down the backs of the pads, and then at each corner of the pad.

Ezookiel wrote:Well, thanks for the suggestions, but whatever it was it was solved by pulling them out and putting them back in.
The shims I was referring to are the very thin metal plates that went down the backs of the pads, and then at each corner of the pad.

"Anti-rattle springs".

You guessed it, if they are not fitted properly (as in not seated squarely) they will cause more problems than they solve...