I have a 1991 lincoln mark vii. The abs and brake light are on and the brakes have no power. there is power at the for 2relay and to the motor and the motor seems to be running but nothing. Car did sit for 4 years but brakes worked 2 months then stoppe. any suggestions would be great. thanks tom
Have you checked the brake fluid? A wild guess would be that a seal or more failed due to old age, sitting for 4 years, or being pushed into a corroded portion on a cylinder that it hasn’t seen in four years, and the fluid has left the system.
You need to start from scratch and have the entire system evaluated. This thing is way too old and sat way too long to assume a simple fix.
I agree with @the same mountainbike; that it is most likely a fluid problem. Because the rear brake lines see more debris from the road…it’s normally a bad line that has a leak.
First check the inside sidewall of the tires for fluid (oily) areas. THis would mean a wheel cylinder or Caliper is leaking.
fill the master cylinder and have someone pump the brake pedal while you watch under the car for fluid dripping. This would indicate a line needs to be replaced.
1991…The ABS systems used back then were little more than prototypes…They were complex and failure-prone…Few car models were equipped with them. Pump and accumulator failures were likely to disable the entire brake system…Bosch made most of them…Good Luck…