My B2 LR started leaking out of the p-brake arm and upon swapping a half functional, p-brake is junk, found a C4 LR caliper that i recently took off our C4 and it looks the same and semi seemed to bot right in. Now they are different in leading and trailing position so just swap L and R. May have to test this out since i need to rebuild both of my good rear calipers for the 4k soon. The replacement on that was on the C4 has a junk p-brake mechanism even though it was "new". They always seem to f-up when rebuilding these things or NO-ONE knows how to really put the piston back.