Seville V8-273 4.5L (1989)
Brake Hydraulic Unit: Service and Repair
Depressurizing Hydraulic Accumulator
The anti-lock brake system pump/motor assembly will keep the hydraulic charged to a pressure between approximately 2000-2600 psi, anytime the
ignition switch is in the RUN position. The pump/motor assembly cannot run if the ignition switch is off, or if either battery cable is disconnected.
Disconnecting the pressure switch connector or the pump/motor connector from the hydraulic unit will also prevent the pump from operating. Unless
otherwise specified, the hydraulic accumulator should be depressurized before working on any portion of the hydraulic system. The following procedure
should be used to depressurize the hydraulic accumulator. To depressurize accumulator, proceed as follows:
1.
With ignition switch turned to the Off position, pressure switch disconnected, pump motor connector disconnected or battery ground cable
disconnected, pump the brake pedal a minimum of 25 times using approximately 50 lbs of force.
2.
A noticeable change in pedal feel will occur then the accumulator is discharged.
3.
When a definite increase in pedal effort is felt, stroke pedal a few additional times. This should remove all hydraulic pressure from the system.
