I am currently replacing my rear calipers with new OE ones, they came with two copper washers per caliper... and I have no idea where they go. No instructions or anything. My current ones dont appear to have any copper washers anywhere..... Anyone got any ideas?

 

They seal the brake line at the caliper. Slip one over the end of the line when you screw the line into the caliper.

 

You probably have them on the line right now and just cant tell. They have a tendency to get stuck on the brake line over the years, make sure to check on this so you don't accidentally double them up. But like slartibartfast said, one goes on either side of the line and then you put the bolt through. They are crush washers that make a seal on the fitting.

 

Yeah this is exactly what it was...

But now even after I bled the rears the pedal still goes to the floor. Do I need to rebleed all 4? I don't think its possible that air would have worked its way into the fronts.