Not locost - but the answer could be relevant to someone so i'm posting here.

Got my 05 focus serviced. Had new disks and pads on the front. Rear pads where replaced 12k miles ago. During the service they where supposed to inspect rears and copper grease as appropriate which i believe they did.

After service the rear pads have squealed at low pressure breaking. Much worse in the rain.

Garage said it needs new pads to cure it. I said it had them 12k ago. They said you need to use ford pads. I said it did have fords put on by the garage i bought it from. I then reminded them it started post service and they where not happy with me implying it was something they did, they've said they'll rough them up and that should stop the noise.

Does this sound right to you ?
What are the likely causes of the squealing noise?

isn't there some sort of metal plate called an anti squeal shim? usually needs greasing up.

Squeeling can come from the friction material or the pad backing. On Renaults (for example) the squeel commonly comes from the back of the pad and using some copper slip on it tends to improve things somewhat.... Roughing up the pads will obviously work if its the friction material. May make diddly squat difference though....

On some Renaults the answer usually is "they do that, sir"....

Some useful info

http://pages.sbcglobal.net/gorf/bmwtips/brakesqueal.html

Low pressure braking? Definitely sounds like the edge of the new pad rubbing against the wear pattern on the disc (the steel rusts slightly where the pad doesn't touch - new pad = slightly wider wear surface).

My Toyota used to do this - my friendly mechanic carefully took the rusty edge off the disc with an angry grinder, and no more squealing!

except the pads that are squealing have 12k miles on them.

Interestingly that article talks about sanding the disks not the pads, the opposite of what the mechanic said he'd do.

Well with everything else that's happened I suspect this is the last time they'll be seeing my car unless something special happens tomorrow shame as they're so close and specialise in the marque.

I had a similar problem many years ago, can't remember the car but its supposedly due to dust building up under the pads. I cured it by cutting a slot across the face of the pads, 2 hacksaw blades wide. (Some pads have this moulded in from new)

Squealing can occur from getting grease on the friction surface of the pad.

If they take the pads out and give them a good clean, grease them up in the guides and pop them back in then this should fix the noise. It could be un related to what they did though as squealing has many causes and it may just be coincidence.

Some cars will always be noisy by poor design. Back up an older Izuzu trooper and they will moan no matter what.

Anyhow, in your case the first step is to service the brakes. If you chamfer the edges of the pads, sand the hard surface off and clean the dust out you will probably end your troubles. A brake service should consist of that, and lubing the slides/pins as required. Some will use anti-squeal lube or adhesive, other won't.

The "ever since you worked on my car" thing is never a good one. Mechanics hear that all the time from people trying to BS them for free repairs, or just being dumb. IE "ever since you replaced my super-noisy broken muffler, now my belt squeals". In reality the belt always squealed, just couldn't hear it over the muffler. Anyhow, because of those, mechanics tend to get a little miffed when they hear "ever since you" even if it is a viable complaint.

Both bits of advice are from a mechanic with 10yrs experience btw .
Cheers.

well i'm sat here miffed at the moment.

Needed a warranty job doing. They agreed to do it, i asked if they wanted to call warranty company before booking car in - nope.

Took car to them on a date later than i wanted so they had the whole day.

Got there and no one about, after 20 minutes bloke from another unit says "lee's just called, he's going to be late can you give the keys to me". I reluctantly do.

I call the garage 30 mins later to make sure they've got my car, no answer, repeat after an hour, two and finally at mid day they answer. Just starting the job, spoke to the warranty company and had argument over size of job blah blah. I remind them about the brakes as well.

5:25 I call them as they close in 5 minutes to see what's happening, should i go down to pay. Sorry, nope, not ready, will be in a bit.

7pm i get a call, just starting on the brakes, can you call in tomorrow at 8:30 to collect.

Well 8:25 i get a call (i live 5 minutes away). Just doing the brakes, does it do it less when you've been driving for a while (answer is yes). Ok, car will be ready in 30 mins.

Happy, no.
Late for work, yes,
Is my boss happy, no.
Will i be able to park when i get to work, no (so i'll end up on the road with lorrys squeezing past and we've had a number of cars damaged!)

Brake squeal, turn the radio up!!

They do that sir!

To be honest its a problem you can worry about and fuss over, or just ignore as it will do no harm.

I generally have the radio turned up pretty loud in my BMW 525 tds at the moment to disguise the fact that the ECU/electronic fuel pump seems to be f**king around with the injection timing and one minute it sounds like a tractor and the next a rolls royce.

PS re. work, looks like I may be back on 5 day week next week for the first time since december!

Ok, got car back, everything fixed, saw the EGR valve with a nice coating of sticky soot in it. Brakes are back to how they where pre service.

Yes i was ranting this morning, garage have done a good job.