Pad Rattle.. Will shims stop it?

[BMWTurbo]

Hi Guys,

I've noticed that since fitting my QFM pads I have a pad rattle on the front when going over sharp bumps on the road. I initially noticed a slight knock on the rear, but that seems to have settled down.

Tha inside front pad has the claw shape that fits firmly into the single piston on the single piston sliding caliper. I haven't noticed excesive run out on the front rotors, they were new with the pads and I've since replaced the front wheel bearing/hubs also, so its all nice and tight on the front.

Is there anything special I should be looking at here or will any shim that is somwhere near the right size work? I don't remember the factory ones having shims that I could use else I would have put them on. Vaguely remember talking to Greg about it when I bought it all, but can't remember the outcome.

[bpm]

Shims won't help. If it still has the anti rattle springs you can bend them to add more tension. Or you can use that anti squeak stuff, basically silicon that glues the pads to the caliper to stop them rattling

[BMWTurbo]

Shims won't help. If it still has the anti rattle springs you can bend them to add more tension. Or you can use that anti squeak stuff, basically silicon that glues the pads to the caliper to stop them rattling

What is the purpose of the shims? Serious question.

I'm almost certain it's the outside pad making all the noise, as the inside can hardly move relative to be captured in the piston.

[bpm]

If you are talking BMW shit they have a large spring on the outside of the caliper to stop the outside pad rattling. Is it still there? If you drive with light pressure on the brake dies the rattle stop?

[BMWTurbo]

yes and yes. I have been searching for rattles for a fair while now and am certain it's the pads rattling. Front suspension have been apart many many times and checked etc.

So I am starting to wonder i the pads are the incorrect size and the antirattle spring isn't holding enough force due to the 'T' section being too small. I'm pretty certain even with the spring in place I could rattle the outside pad.

[snavy]

I have probably used QFM pads about 100 times. Some of them are noisy! Nothing ya can do except change brands. How are your slides?

[tut]

not really a solution, but if you have your old non-rattling pads, you can send them to QFM, and they'll put new friction material on it. that way you're sure it's not the pad backplate.

[BMWTurbo]

Cheers Guys... They are rattly, but I thought Glenn mentioned shims or something a while back, can't find the info now though.

Pretty certain I tossed the old pads and couldn't use the SS shims from them with the QFM's else I would have.

[Uncle Arthur]

SS shims help in preventing heat soak into the caliper pistons and then to the brake fluid.