Irritating 2 year old wheel grating noise on light breaking...

[Marlowe]

Hoping someone can help with this mystery noise - I drive an 06 GTI and have a loud grating noise from the rear near side corner when braking with the first third of brake pedal travel that no-one has been able to identify.

This has been going on for two years now and has been driving me mad since it started...I've recorded the noise on my phone - it can be heard at http://vocaroo.com/i/s1umijqfaSwm

At first I thought it was a warped disc after taking the car once to the Nurburgring, so I replaced the rear pads and discs with brembo equivalents. This didn't fix so I took it to my local independant garage - they had no idea. I then took it to the local VW dealer. They confirmed a noise, had three seperate technicians and the service manager drive it, took down the braking and then the suspension components and couldn't find it, so decided it was 'normal' as it didn't cause an issue. Effectively any of the obvious causes eg pads, discs, suspension, wheel bearings, all were covered and the car was given a clean bill of health.

Unfortunately this leaves me with a car which drives perfectly fine but with a noise that drives me mad, and which I know when I come to sell will come back to bite me in the posterior.

Has anyone else had this problem and located the cause? It's got me completely baffled.

Thanks!

[DaveB@Vagbremtechnic]

Its rotational so can only be discs and pads.

My guess would be a sticky piston or a handbrake mechanism that isn't coming off fully. Its not something you would notice on the ramp.

Buy a rear seal kit for £15 and send them somebody who knows what they're doing to rebuild them and polish the piston.

If you can wait till the end of September which is when I'm back for longer than 4 days I can do it for you for nothing if you can afford the downtime of sending me the Caliper. Think I've got a pair that I bought of bendy holding the garage door open I'll take a look.

[Marlowe]

Dave, very grateful for the response - kicking myself for not having thought to have asked years ago now. I'll see if I can source a kit & a local specialist as I don't want to put you out but very greatly appreciate the offer. Thanks again for the input. Glad to finally be moving towards resolving the bloody noise.

[Marlowe]

Just a quick update on this. Struggling to locate the correct kit for the caliper due to not being able to identify if the caliper piston diameter is 38mm or 41mm. It's a TRW caliper, has a casting mark that appears to read 15 16 and then something unintelligible due to paint corrosion. Is this a 41mm seal? Also, any recommendations on places to buy?

Cheers :)

[bacillus]

A standard 06 rear gti caliper should have a 38mm piston.

Get in touch with DaveB and I'm sure he'll sort you out.