tbennett017

I did a front brake/rotor change on my C4 last night. What is the collective opinion on the brake anti-squeal shims with the springs that fit into the pistons?

I have read the DIY's on the subject, and some say to treat them like the under-tray (with the same controversy?) and heave them... but I am a fan of trying to understand the original intent behind them...

Since I have put the car back together, brakes work fine, but the pedal is softer than I'd like. Do these affect that kind of feel? (In removing them they got a little bent, and they were stuck to the old pads, where in my new ones there is a bit of mechanical space between, as the bond is new. I think its like layers of lettuce in a sandwich... a little bit of gap due to the mechanical mis-match...)

I am going to do the C4 bleed again tonight, but I didn't crack open the system anywhere, so I don't know if its hydraulic or mechanical (the gaps or squishiness)

Any thoughts?

Thanks.

Indycam

"Do these affect that kind of feel?"
Anti squeal or the lack of same , should not make a pedal feel different .

"the original intent behind them"
To keep the brakes from squealing .

Did you use a solvent cleaning on the disks ?
Have you done the bedding / break in on the pads / disks ?

tbennett017

I did a solvent wash on the rotors after I put them on.
It was wet/raining last night.. so I haven't done a proper bedding in yet.. just a drive around the block..

Indycam

Once they are , they will "grab" more I think .
When they grab more , maybe you will not feel the pedal to be softish .

blake

+1. You've got to bed those brakes by heating them up. Braking is really asbestos-to-asbestos contact rather than asbestos-to-rotor contact.

Let us know if the brakes are still slushy after the bedding process...

-Blake

dcbailey

I recently did my front pads, and used a putty scraper to separate the anti squeal shims from the old pads. This has been suggested before on the How-to, and it worked like a charm. I, too, left them off the replacements, and now my brakes are squealing quite a bit with gentle braking. I'm going to put them back on this weekend, if the weather warms up, to see whether it makes a difference. On my back brakes, the squeal shims are attached to a metal plate, and are much easier to handle.

I didn't use any brake cleaner when I changed mine. Does this really matter? One would think that they will get dirty again after the first drive, so what's the importance of using this?

pat056

+1 on bedding them in. I did a rear rotor change a couple of weeks ago on my race car. I've driven 2x for a total of about 10 miles. the 1st time the brakes were downright snongy. By the end of the 2nd heat cycle, the breaks were stopping much better. I'll be at the track next week so I'll really know how there's going to do then.
This soft pedal can happen w/just pad changes, until they are bedded in.

boxsey911

A nice smear of copper grease on the backing plates of the pads should stop the squeal. I prefer this to the anti-squeal shims because I'm regularly swapping pads in and out.

Indycam

"Does this really matter? "
If the rotors are coated with an anti rust treatment and they don't get cleaned , that might be some of the cause of the pedal feel .
If it was a race car and the rotors did not get cleaned , yes it would matter .
On a street car that gets oily water up onto the rotors now and then , it probably does not matter as much if you pre clean the rotors .

Steven C.

Clean the he.. out of new rotors because if you don't the grease will get into the pad and ruin it. I clean new rotors with brake clean first and then a soft brush and soap and water. As for the anti squeal plates I always put them back on my street cars and have never had a squeal. You do not need to clean the backing plate of the pad before sticking new shims on but if you are re-using the old shims make sure they are still sticky or they will not work.

tbennett017

I did a full C4 re-bleed (accumulation tank, block valves, and each caliper) and the car is quite a bit better. I only saw the tiniest of bubbles, 2, or 3 about the size of a ball-point in a pen go by, but it has made a big improvement in the pedal feel. It doesn't travel as much as it did before..

go figure. I still need to do the bedding in heat cycle... but bleeding helps, even if you didn't open up the system.

deep_uv

No mushrooms! Mine don't squeal a bit. Don't grease the back of the backing plates where the pistons meet meet the back of the brake pads. If your brake pads don't come with the backing pads, buy the aftermarket ones. Only grease on the sides of the backing plates where they make contact with the spring plates on the caliper.

n1ne11

Can anybody comment on this?






My plan is no antisqueal shims and removing the backing plate of the Brembo HP2000's (they have 20k km on them but still having a lot of material but it looks like hard, uneven, burnt paste between the backing plate (which is coming off) and the pad metal plate itself). Maybe polish a bit this side of the pads to have them "plane and clean".

Thank you