I fitted new brake pads and discs all round yesterday. I noticed that the shims on the front pads are well past their best, with severe corrosion in places. For the time being I have cleaned these up as best as I can but is it absolutlely necessary to run with these shims in place?
I notice from the Ma5da Racing regulations that these are not required for that championship.
I have a theory that the brake pedal will feel a little firmer and more direct without the shims, but will I suffer from terrible brake squeal as a result. The new pads are EBC Ultimax (Black Stuff road pads).
hi niggle, had the same problem bought new discs n pads went fit them and found the anti squeal shims rusted away! but used copper slip and so far they hav been dead quiet, plus u may find quality pads come with their own anti squeal pad glued to them (mintex dont!)[:$]
Thanks, Goochie. I will definitely try without the shims. All the metal to metal interfaces are greased up with Copper Ease so I’m hoping they will be OK. I usually strip the brakes and down, clean and regrease annually anyway. A full set of shims and anti-rattle springs is only £12.51 from MX-5 parts but the springs are all stainless and the old ones cleaned up nicely with a brass wire brush and some brake cleaner.
The only other car that I have owned that had anti-squeal shims on the brake pads was a 1990 Rover 414. I ditched the shims on this car and the brakes were still fine.
The idea of the shims/backing plates is apparently to give something soft that the caliper can bite into and prevent further movement. The alternative approach is to let it move and use copper grease to reduce the squeal that results. Either way they’re safe; it’s really all about trying to prevent noise.
By way of an update, I removed all of the shims and hold-off springs at the weekend. The brake pedal is now a lot firmer and inspires more confidence. No brake squeal evident yet. No doubt my brakes will be even better still when I have fixed the leaking OSF caliper…
Good timing, Rob. I had the first squealing for the first time just last week. This is nine months after I removed the shims. I noticed a fair bit of surface rust on the discs after the recent downpours. The rust has now scrubbed off and the squealing seems to have gone away. I will be stripping the brakes down and cleaning them in a couple of months so I might try some of the proper Bendix blue-goo, no complaints about the way that Copper Ease has performed though - I still have about 0.25kg of the stuff left so it would be daft not to use it.
UPDATE: I have just bought a tube of Mintex CeraTec paste off ebay.