Was getting a bad grinding,so i took the rears off and drivers side was fine with plenty of pad left ,then took off passenger side rear rotor and the outer was fine but the inner was toast....pad was fine but was only touching like 3/4 of an inch of rotor,bottom half of inner rotor was rusty. I took out the slide pins and they came out fine greased them up and then reassembled. Took it for a ride on the expressway and put the brakes on slightly and the whole rear started shaking. I retracted the e-brake by turning it clockwise. So are my calipers bad?

 

Kinda confused by your description honestly. You saying that the inner pad was only making contact with the top of the rotor and the bottom of the rotor got rusty from lack of use?

 

Yes

 

Happened on my parents Yukon too. It's problem was that the pads were too tight in their clips and couldn't slide around properly. So with the new set I just ground down the edges where it sits in the bracket slightly so they could slide freely and it didn't have the problem again