No shims on new style front calipers

[tojo82]

Hi all I've got some new 2017 front calipers never used and was curious that there are no shims on the back of the pads. It doesn't look like there are meant to be any either? Can anyone advise please?

[Seeker]

There's none shown on the parts diagram:
https://www.fowlersparts.co.uk/parts.../front-caliper

[Bibio]

they might have a ceramic coating. what ever you do dont use copper grease on the backs of the pads coz if it gets onto the piston seals it will eat them.

[Chris_SVS]

Not all pads have them, as above re copper grease. Red rubber grease in the boots etc

[tojo82]

Thanks all I would have copper greased them for sure without your advice

[mikerj]

Originally Posted by Bibio

they might have a ceramic coating. what ever you do dont use copper grease on the backs of the pads coz if it gets onto the piston seals it will eat them.

There are supposedly better modern alternative to copper grease, copper grease has been used on brakes for many years (at least the last 30-40 years) with no evidence to suggest it's causing failures.

[Chris_SVS]

I don't know anything about eating or swelling of seals but I've never read a service manual that recommends putting copper grease/slip anywhere near brake pads. (I'm even looking at a service manual while typing this post)

Proper maintenance, keep stuff clean, only put greases etc where the manual says to..

(BF) = Brake Fluid on the inner seal
(S) = Silicone Grease on the dust deal

[Seeker]

The reason we use (or used to use) Copaslip was to reduce or eliminate brake squeal. It was a car thing from the late 70s early 80s and migrated over to bikes when disks were fitted. I always used to apply it on my cars and never suffered from brake squeal but since I never fitted new pads without it I don't know if it was doing anything.

Seal materials have changed, maybe they are more susceptible to damage from Copaslip these days, or maybe it was never needed. I never had any issues on my cars with seal damage.

[Chris_SVS]

All it would do is dampen the noise, not cure the reason for the squeal. Contamination, misalignment, poor maintenance etc

[Seeker]

Originally Posted by Chris_SVS

All it would do is dampen the noise, not cure the reason for the squeal. Contamination, misalignment, poor maintenance etc

I think the idea was that the squeal was generated by the piston to shim contact. Using Copaslip used to be a common procedure, so much so that when you bought the pads at a shop they would remind you to do it. I asked our MT section where I was stationed and they, too, recommended it as a preventative action.