Parking brake/oil on pad/high pitched squeal

[jbyler]

I have a 2003 GMC Yukon Denali. A high pitched squeaking noise that just didn't sound like the brakes started happening after I had my rear brakes replaced (ceramic, have been disassembled twice to ensure no problems). I stayed on the mechanic...again, they checked the brakes, nothing, but found a leak in the rear axle differential seal - leaking a slight amount of oil onto the emergency brake pad, which caused it to "go shiny" (like a mirror) and is now making this horrendous high pitched sound. It's being fixed tomorrow at the shop to the tune of $350, but why would oil on an emergency brake pad be squeaking like that?? It sounds to me like something is scraping/not releasing from when the parking brake is set then released. Anyone have any knowledge on emergency brake/pads/squeaks?

 

[Rivieraracing]

The parking brakes on our trucks suck because of a bad design, even when you adjust them perfectly they are always rubbing somewhat and wearing out prematurely!