RichS11

Hi guys,

Need some advice as I'm struggling here and I don't know what else to look at. The story so far....

Put on some LS4 calipers as an upgrade on my GS. I used the pads and discs that came with the calipers. Used copper grease in the right places and lubricated the brake pads up on the rear of the pad. I took the car out for a run and under light braking/feathering, the car had a really loud sound, similar to that of a whale speaking or the same noise a push bike makes when braking!! It was not a high pitched squeak or metal on metal, just a load moaning noise.

I thought the pads were shot so I put new ones on, EBC pads with less metal in them and organic. I put them in with the noise cancelling pad and shims on the back and with copper grease again. Took the car out and the same noise was happening.

Today I decided to look at the discs and noticed there was a small lip that the new pads were touching on both the inside and outside of the disc. I could see that the pads were not making full contact with the disc because of this lip, so I ground it down. Took the car out again and BOOM, same f***ing noise.

I've had enough now as I have no idea what to do. I can't seem to find a similar post online apart from on a BMW forum for the M5/M6 that have the same issue, but the guys there didn't seem to fix it. The noise is that loud, it makes people turn around and these people are quarter mile up the road!!

Has anyone had something similar and what can I try next?

Thanks for any help you can offer fellas!

RichS11

This is the exact noise I'm getting....


But I have checked this on my car and it's aligned perfectly

NorthStyle

iTrader: (16)

Does it do this all the time or only when the brakes are cold? My old slotted/drilled rotors used to do that until they were warmed up.

RichS11

Hey North. This is happening once the discs warm up and gets worse the more I drive.

RichS11

I'm going to do a proper bedding in procedure tomorrow. I need to try that and go from there. The fact this has happened on the old pads and the new ones, it can't be a pad issue.

I think it may be related to the heat shield touching the calipers perhaps or the breaking in procedure needs doing? Ceramic pads for me if these don't work. £30 down the drain!

vipXjunky

iTrader: (28)

calipers are bolted down real good right? is this coming from one or both side? I had a similar problem and it ended up being my rear brake pads. are you using RCA for the upgrade or did you do the shaving method?

RichS11

Hey dude. Yeah they are nice and tight and I'm using Figs RCA's. I had to bend the dust shield and I think it may still be touching the caliper. I doubt it's linked to it but I'll try to bend it a bit more so they're not touching.

vipXjunky

iTrader: (28)

caliper isn't seized right? seals are good?

RichS11

One of the seals is a bit tatty but all the pistons slide freely. I was looking online and noticed that the clip on shim on the back of the caliper is not the only shim I should have in there. I should have some sort of spacer plate too. I'm going to look into this as that might be my issue.

RichS11

So I carried out a full break in and no luck, however after looking at the discs, the left hand side which is the noisey side, has an odd pattern on the disk. The lower half of the disc, closer to the hub, has not bedded in with nice smooth lines unlike the other side. I have a feeling there's an issue with the pad not sliding across all the way under light braking. If this is the case I'll take the caliper out and clean it up to see if the pads are not moving freely.