Does any one know why the brake assembly motor keeps running in the MC of a 87 GN even when the car is on, is that why I lost my brakes, Is there a solution to this problem? thanks.

sounds like you need a new powermaster. Go to advanced autoparts and you should be able to pick one up for about 210 bucks. that includes the accumulator.

or switch over to vacuum brake setup. i did just that with the 87 Turbo T that i just sold. easy project and if you get the parts out of a junkyard it can be real cheap. i bought a kit with nice instructions off of a turbobuicks.com board member for $135.

If you can get a POWERMASTER assembly for 210 bucks go for it. Sounds like the pump is weak-good to keep these cars as original as possible. Getting these brake parts individually will keep a man broke.