Originally Posted By: SubLGT
Do coated shims sometimes require a lubricant?
The FSM for my 2005 Subaru states to use lube for the shims. But the OEM pad and shim kit for my rear brakes did not include lube, and the FSM was not specific about exactly where to lube the shims. The shims have a smooth black coating on them.
I have some M77 on hand to lube the stainless steel pad clips.
A bit late to the game but here's my take on whether or not to lubricate brake pad shims.
Many claim you don't need to lubricate the shims and I was under that impression as well. However, back in 2005, my factory new Subaru Impreza developed squeaky rear brakes after its first Winter. Upon disassembly it turns out that road salt, grit and grime had "washed" its way between the shims (the black coated variety like yours) and the caliper/pad. There was no sign of residual lube so it appears that Subaru installed the shims dry at the factory. I cleaned and reassembled everything lubing the shims in the process. The brakes remained squeak free until the pads wore out many years later.
So now, whenever I do a brake job I lube the shims to prevent water spray from washing dirt and grime between the shims and other surfaces. Use something thick that will resist washout.