[bork]

Thus no cruise control. Can a bad/worn master cylinder cause this? I bleed brakes 2 x now & still not as firm as I would like & pedal does show slow sinking.

 

[Abbey]

I hope someone answers this because I have the same problem and I have changed the master cylinder and I still have a sinking pedal????

 

[Mr_Roboto]

There are two causes of a sinking pedal that goes all the way to the floor (without fluid lost). First is the master cylinder, the second is the Rear Anti-Lock Brake valve.

You can also get a "sinking" sensation because of the vacuum pump as the boost increases with time stopped. However, this will stabalize and not take the pedal to the floor.

 

[Abbey]

Is there any adjustment to the anti-lock valve?

 

[bork]

I cleaned off the speed sensor on differental & still no change. installed new sensor from dealer, about 24.00 ? & all fixed & cruise control works again! Thanks everyone.

 

[Mik]

my 91 wouldn't have ABS would it?

cuz i have the same problem, but i haven't replaced the MC yet

 

[bork]

My brakes still dont feel right , so I asked someone what vacuum should be since I measured at 16 . They said minimum 25. Also I noticed brake light coming on here & there & would go out if I reved engine. Installed new Vpump today & at idle it quickly shot up to 25lbs. & brakes feel normal now.