Hi all,

Newbie Audi owner here, recently bought an A4 B7.

After some advise with a strange squeal which didn't appear when I test drove the car, which seems to be related to wheel speed, and stops when braking.

When warm it appears (I assume as it only starts after 20 mins or so) I get a constant squeal from drivers side wheel.

I assumed caliper sticking so had it checked by a garage who 'cleaned up the brakes and regressed them' and said they were basically new, and all good.

Since then I have a knock when braking, and the squeal continues on the same side.

I've shoved my phone behind the wheel and got a pic of what looks like a caliper pin without a boot, but it may be something else! I am wondering whether that could be related, however I've never really noticed the wheel getting excessively hot, however it's not had any very long drives. 

I've noticed it seems to start after a sharp turn but this may be coincidental!

Any suggestions where to start with these, or what they could be?! 

Thanks in advance!

30 minutes ago, adj said:

Hi all,

Newbie Audi owner here, recently bought an A4 B7.

After some advise with a strange squeal which didn't appear when I test drove the car, which seems to be related to wheel speed, and stops when braking.

When warm it appears (I assume as it only starts after 20 mins or so) I get a constant squeal from drivers side wheel.

I assumed caliper sticking so had it checked by a garage who 'cleaned up the brakes and regressed them' and said they were basically new, and all good.

Since then I have a knock when braking, and the squeal continues on the same side.

I've shoved my phone behind the wheel and got a pic of what looks like a caliper pin without a boot, but it may be something else! I am wondering whether that could be related, however I've never really noticed the wheel getting excessively hot, however it's not had any very long drives. 

I've noticed it seems to start after a sharp turn but this may be coincidental!

Any suggestions where to start with these, or what they could be?! 

Thanks in advance!

Hi the greasing of the calliper could be a problem as you should not grease the back of the pads as they are fitted with a high temp rubber anti squeal cover which when heated semi bonds to the outer part of the calliper, the same with the piston side which also has the steel insert for the piston inner but the outer edge of the piston also bonds with the rubber backing on the pad, I think your brake knock is due to wear on the brake carrier as the locating pins for the pad guides wear and allow movement between the pad and carrier.

Steve.

Thanks for this, sounds like maybe when they 'cleaned then up' the high temp rubber let go maybe?!

I guess that could cause the knock, as it wasn't noticeable before!

I'll see if I can get someone to replace the caliper pins and boots and see how that goes, I don't think the pads are OEM as I have a euro car parts invoice for them with the history I think.

A really annoying issue that didn't present when I test drove, and only seems to appear at slow speeds when warm, or triggered by certain steering angles, and seems to ease if I steer a bit!

Thanks for your help.

I've had the brakes checked by a garage and apparently there are no issues with the calipers etc, they wound the caliper back etc and checked it all.

Apparently likely a suspension knock, and the squeal for the last couple of days has been pretty much non existent.

Any ideas what suspension would make a single metallic knock only occasionally on braking?!

Apparently there are quite a few worn bushes so trying to narrow it down!

Thanks again!

Could it be the suspension arm? 

Or engine mount? 

On 1/21/2024 at 11:22 AM, adj said:

I've had the brakes checked by a garage and apparently there are no issues with the calipers etc, they wound the caliper back etc and checked it all.

Apparently likely a suspension knock, and the squeal for the last couple of days has been pretty much non existent.

Any ideas what suspension would make a single metallic knock only occasionally on braking?!

Apparently there are quite a few worn bushes so trying to narrow it down!

Thanks again!

I have this (the knock), I've narrowed it down to the upper control arms.