Disassembly

POWERMASTER UNIT DISASSEMBLY

WARNING: Failure to fully depressurize Powermaster unit before performing service operations could result in injury to service personnel and damage to painted surfaces.

Exploded View Of Powermaster Assembly:

1. Depressurize Powermaster by turning ignition off, applying and releasing brake pedal a minimum of 10 times using approximately 50 pounds force on the pedal.
2. Remove reservoir cover and diaphragm (32). Empty fluid from reservoir (33).

Figure 2 Pressure Switch:

3. If installed:
a. Remove pressure switch (1) and O-ring (2).

Figure 3 Accumulator:

b. Remove accumulator (3) and O-ring (4).

Figure 4 E-H Pump And Pressure Hose:

c. Remove Electro-Hydraulic (E-H) pump (8) and pressure hose assembly (11).

Figure 5 Sump Hose, Tube Nut & Assembly, and Motor and Pump Brackets:

d. Remove sump hose (9), clamps (10), tube and nut assembly (12), and brackets (14 and 15).

CAUTION: Use care not to scratch or otherwise damage outside diameter sealing surface at pushrod end of power piston assembly (25) and bores in Powermaster body (39). These are primary sealing surfaces for this unit.

4. Remove retainer (18) from groove in Powermaster body (39).
5. Remove boot, retainer, pushrod, power piston group (16 thru 25) by grasping and pulling pushrod.
6. Remove retainer (16) and boot, pushrod, socket group (17) and piston guide (19) from power piston assembly (25).
7. Remove O-ring (20) from piston guide (19) and O-rings (21) from power piston assembly (25) and piston guide (19).
8. Remove reaction body group (22) from power piston assembly.
9. Remove reaction piston (23) and reaction disc (24) from reaction body group (22).

CAUTION: Do not attempt further disassembly of reaction body group (22) or power piston assembly (25). If damage is noted or fault isolated to reaction body group or power piston assembly, they shall be replaced as assemblies.

10. Remove primary piston assembly (26) and secondary piston assembly (27 thru 30) by directing a small amount of compressed air into outlet port at blind end of body, other outlet port plugged.
11. Remove secondary seal (27), spring retainer (28) and primary seal (29) from secondary piston (30).
12. Remove spring (31) from body bore.

Figure 8 Removing Reservoir:

13. Install Powermaster body in vise.

CAUTION: Do not clamp across Powermaster body.

14. Remove reservoir (33) using pry bar (45).
15. Remove reservoir grommets (34 and 35).
16. Remove valve seat and seal (36) and discard.

NOTE: To remove valve seat tap "easy out" into seat and pull straight out.

17. Remove poppet (37) and spring (38) and discard.