90 SC brakes not working

Tunevo

Registered User
1990 SC 5 speed, lost brakes last night, pump not running. Accumulator had stored pressure, but still a hard pedal. At this point I am confused to the issue as I had accumulator charge. Has power to the pump motor.

Anything I should be looking at in specifics? I've seen topics on hard pedal, and I swapped the whole unit with a working spare but no brakes with charge in the accumulator has me stumped. So situation is now no charge (as I let the stored pressure out thinking I had none) and pump not running with power to the motor. Possible pressure switch failure or delay perhaps?

Thanks!
 
  • Accumulator
  • Pressure switch
  • Relay(s)
  • Pump motor
  • Lack of fluid
  • Air in line at the master cylinder after having it apart...best to bench bleed, I think, search here for details
  • Failing/failed multi-wire ignition switch down on the right side of the steering column - this one got me just a few months ago.


Seen this? http://www.sccoia.org/articles/anti-lock-braking-system/
 
Accumulator is good, tested with my spare, was bench bled and tested, no air in system, fluid up to level when checked yesterday with accumulator charged, I guess may be pressure switched as accumulator wasn't discharging fluid pressure to the system when brakes applied. Pump tests ok (disassembled assembly today and applied voltage to verify and motor seems strong).

Just never had brakes fail with a charged accumulator before.
 
No power assist

If you have power to the motor, that eliminates
the pressure switch, relay & power supply(s)
It has to be a bad motor/pump assy if its not running
 
I noticed in your other thread you finally determined it was the pump motor.

Yessir, sad that it only had 90 kms driven on it after tested and installed before it failed. I un-seized and cleaned my old motor and it seems to work. Ive got over 200 kms on it since I changed it, and hasn't let me down...yet.

Thanks for checking up!
 
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