brake problems

[gtojoe]

hey guys ,iam a newbie and just picked up an 87 gn with some brake problems.. the guy just put in a new ( or another ) factory master cylinder and the car has a rear end out of a non turbo car.. the problem is when i apply the brakes the rear tires lock up.. are the rear brakes different in any way .. it also doesnt appear that the proportioning valve is hooked up wrong .. i would appreciate any help ..thanks joe

 

[johnnyttype]

maybe wheel cylinders r leaking causing the brakes to lock up. does this occur in rain or dry...or both?

 

[gtojoe]

it does it all the time ... the rear cyl. look dry i was wondering if the cyl where different or maybe the powermaster is at fault..thanks joe

 

[johnnyttype]

maybe it was off a manual brakes car, miss installed shoes(small shoe in front, big shoe in back), adjustment too tight? dont know too much about the brakes on these cars just throwing some ideas out!

just saw the master cylinder was new or replaced. did u ask the owner before u if it had the problem prior to the replacement of the powermaster unit?

 

[gtojoe]

didnt ask about the condition before and i will check the shoes ..didnt think of that thanks