1989 Cherokee. I've replaced the following:
Pads, rotors, shoes, drums, cylinders, calipers, master brake cylinder.
My brakes are still squishy. Manually bled all 4, still squishy. Went out and bought a pneumatic brake bleeder, bled them again, still squishy. Any ideas?
robert
porportioning valve or still air trapped Try to gravity bleed it Starting farthest away from master cylinder open bleeder and let gravity do its work watching the master not goes dry.@ 5 mins close bleeder and do the same to the rest working closer to the master
thebax2006
If the brake pedal gets hard when you pump the brake pedal a dozen times without the motor running the rear brake shoes are out of adjustment. Since brake shoes don't get "arced' to fit the new brake drums anymore they will need readjusting after putting a couple of hundred miles on the vehicle. I'd clamp off the rubber brake line at each front caliper and test the way the pedal feels to see if it gets better. many ties the front rubber hoses running to the calipers will swell when the pressure is applied and that will cause mushy brake pedal. Clamp off the rear brakes at the rubber hose to the junction by the rear differential to test if the rear brakes are the problem.
?
Not familiar with your car, but i'd look at the flexible brake hoses, as already mentioned, and a possible leaking past the seal master cylinder. If you press down hard on the pedal does it creep to the floor? If so i'd replace the master cylinder. Does it have ABS? I had this same problem on my 1996 Land Rover Discovery after we had to remove the ABS block to replace the rust in, well, a lot of it :). Bled it four or five times. In the end had to connect via the OBD and make the ECU 'bleed itself' by opening each circuit through the ABS block. Just had to ensure fluid was going into the reservoir and open each bleed nipple in sequence. Got a good firm pedal after that.We'd replaced all four discs and pads and flexible pipes with braided hoses so we were stumped until we tried this.
Steven
Brake booster? That is the last thing I can think of that you didn't replace. If you can pump the brake when the car is off and get a stiff pedal, but the brake pedal is squishy during normal driving, then it is more than likely a bad brake booster.
arther
If it bleeds up nice and hard before you start the motor then goes spongy when the motor starts its usually the vacuum booster that causes that.