New brakes squealing quite a bit on a W204

[coffeefuelledtechie]

Hello all,

I had all four discs on my 2011 C180 replaced because they were pretty worn, but the pads were left on as they were fitted by the previous owner and were basically new.

I’ve bedded them in, but they still squeak a bit when braking, though not all the time.

I think they are cheap brake discs (don’t know the brand as the garage fitted them for £250 all in), and reading online that cheap discs and pads are likely to squeak more.

Is it better for me to write off that cost and get decent pads and discs all round, and I guess replace the dust shields while I’m at it? I would like to give this a go myself with some help, so what tools would I require?

 

[ALFAitalia]

In my experience squeaking new brakes are nearly always caused by poor fitment. So anti squeal shims missing (if applicable) poor cleaning and re-lubing of the points the pads rest on (DONT use copper grease here....its an anti seize......not a lubricate. ...ceramic grease is the stuff....and red rubber grease on the boots and new seals if fitted). No grease on the back of the pads (copper is fine here). If Brembo style, the slide pins being left dirty and/or corroded. Also the pads being too tight a fit so they stay touching the disC after application, stick and dont move away from the disc enough....often caused by them having too thick a layer of paint on them and being a tight fit end to end...easily rectified with a small file. Also not breaking them in according to pad makers instruction.....some, like EBC yellow stuff, have some strange brake in routine's. Usually cheap discs are not the cause of squeaking....its just lump of spinning cast iron after all.....the issue with cheap discs is usually warping after a short time or fast corrosion on the upswept areas and the hub due to poor corrosion protection.

 

[Petrol Pete]

Hello and welcome , £250 'all in' for that job is very cheap , it makes you wonder how much time they spent on the job , ie: cleaning/wire brushing ,using the correct lube etc ?

Personally I would not use old pads on new discs , the other way around , new pads on used discs , yes.

 

[toteimerced]

Agreed, the old pads would have been worn to the shape of the old discs, it could take quite a few miles, before the pads have worn to the shape of the new discs, pads are the cheaper parts to replace anyway.

 

[coffeefuelledtechie]

Hmm looks as though it was poor fitting then, which is disappointing as I took it to a tyres and brakes place and they’ve been good with other cars I’ve had with them.

If the discs are fine, reckon I’d be okay replacing the pads myself, or just take them somewhere else to have it all replaced and done properly?

 

[coffeefuelledtechie]

I need to go back to the tyre place today anyway as I need new tyres so I'll mention that the brakes are still squeaking. When I got it back from them last time it did look like they had put copper grease over the backs of the old pads so I'd assume they lubed the rest of it, or if it's as simple as the pads needing to be replaced as well.

 

[coffeefuelledtechie]

Update.

I went back to the tyres and brakes place. Same guy I saw before, “still making a squealing sound?”, absolutely lovely team there. He dismantled everything, cleaned everything up, lubed what needed lubricating, cleaned up the existing pads (they don’t have the specific pads in stock anyway) and noise hasn’t come back. I also got the tracking sorted while I was there.