Functional Check Sequence Test - Powermaster Brake System

1. Turn ignition"ON". The Electro Hydraulic (E.H.) pump will run and then shut off. (Do not allow pump to run more than 20 seconds.)
2. Observe that pump stops at 635-735 psi reading on test gage.(Pressure will settle to a slight lower value after shut off and then remain steady-observe for 1 minute).
3. Slowly bleed off accumulator pressure with bleed valve-returning fluid to pump reservoir. Observe that pump turns on again at 490-530 psi.
4. Have assistant slowly apply brake pedal (reservoir cover off) and hold at steady medium force. Observe pressure gage for indication of continuous pressure drop. Pressure drop rate should not cause pump to recycle within 30 seconds of first apply.

Figure 10 Ports And Terminals:

5. Turn ignition "OFF" and remove pressure switch electrical connector. With ohmmeter connected to switch terminals B/C and ignition "OFF", slowly bleed off accumulator pressure. B/C should close at 355-435 psi. This is the low pressure warning signal.
6. Continue to bleed off accumulator pressure and note sudden drop off in gage pressure reading at 200-330 psi. This sudden drop is the accumulator precharge pressure.
7. Assure that pump sump fluid level is at the "FULL" mark on the inside of the reservoir when accumulator is fully depressurized.
8. Turn ignition "ON" and cycle pump several times to remove air by opening and closing bleed valve. Pump "ON" time should now be less than 10 seconds each cycle.
9. During pump "ON/OFF" cycles, note sump reservoir fluid level. It will normally be just covering the sump hose port when pump is "OFF", and 1/2 full when pump comes "ON".