Hummer H1 (2002+). Manual - part 133

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 Steering System  8-39

®

05745159

POWER STEERING PUMP REPAIR

Disassembly 

 (Figures 8-72 through 8-77)

1.

Suction fluid from reservoir and disconnect fluid reservoir 
hose from pump.

2.

Remove power steering pump pulley and bracket.

3.

Drain fluid from pump assembly  (Figure 8-72).

4.

Remove two mounting studs from pump assembly.

NOTE: Fitting assembly is spring loaded. Remove care-
fully to avoid losing parts.

5.

Remove fitting assembly and O-ring seal. Discard O-ring
seal.

6.

Remove flow control valve and valve spring from pump
body.

Figure 8-72:   Pump Assembly

Figure 8-73:   Reservoir Removal

CAUTION: Do not overtighten vise as pump body could
be distorted.

7.

Place pump body in vise  (Figure 8-73).

8.

Tap lightly around edge of housing.

9.

Remove housing and O-ring seal from pump body.
Discard O-ring seal.

10. Remove three O-ring seals from pump body and discard.

(Figure 8-74).

11. Remove magnet from pump body and discard.

7-S08-062.2

HOUSING

PUMP BODY

MOUNTING STUD

VALVE SPRING

O-RING SEAL

FITTING ASSEMBLY

FLOW CONTROL VALVE

PUMP

ASSEMBLY

MOUNTING STUD

HOUSING

O-RING SEAL

PUMP BODY

PUMP
SHAFT

4-1-00

8-40

Steering System

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®

Figure 8-74:   “O” Ring Seal Removal

12. Remove retaining ring from pump body  (Figure 8-75).

13. Remove end plate and pressure plate spring from pump

body.

Figure 8-75:   End Plate Removal

CAUTION: If end of driveshaft in steering pump housing
is corroded, clean with an abrasive crocus cloth before
removing shaft. Failure to do so may result in damage to
shaft bushing. If bushing is damaged, replace power
steering pump assembly.

14. Tap lightly on driveshaft until pressure plate is free

15.  Remove pressure plate (Figure 8-76).

16. Remove pump ring and vanes from pump rotor.

17. Remove driveshaft, rotor, and thrust plate assembly from

pump body.

18. Remove retaining ring from driveshaft.

19. Remove rotor from driveshaft.

20. Remove thrust plate from driveshaft.

21. Remove dowel pins from pump body.

Figure 8-76:   Pressure Plate and Rotor  Removal

Figure 8-77:   Seal Removal

22. Remove two O-ring seals from pump body. Discard O-

ring seals (Figure 8-77).

23. Remove driveshaft seal from pump body. Discard

driveshaft seal.

O-RING SEAL

O-RING

MAGNET

PUMP BODY

SEALS

RETAINING RING

PRESSURE PLATE SPRING

END PLATE

PUMP BODY

PRESSURE PLATE

PUMP RING

RETAINING RING

THRUST PLATE

PUMP BODY

VANES

ROTOR

DRIVESHAFT

DOWEL PINS

O-RING SEALS

PUMP BODY

DRIVESHAFT

SEAL

 4-1-00

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 Steering System  8-41

®

05745159

Cleaning and Inspection 

 (Figure 8-78)

NOTE: Clean all components, examine for wear or dam-
age, and replace if necessary.

1.

Inspect flow control valve and valve spring for damage.

2.

Inspect studs for damage.

3.

Inspect fitting for damage.

4.

Inspect housing for damage.

5.

Inspect remaining components for damage. Replace power
steering pump if any component is damaged.

Figure 8-78:   Cleaning and Inspection

POWER STEERING PUMP

STUD

FLOW CONTROL VALVE

FITTING

VALVE SPRING

STUD

PUMP BODY

PRESSURE
   PLATE

ROTOR

DRIVESHAFT

HOUSING

4-1-00

8-42

Steering System

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Assembly 

 (Figures 8-72 through 8-83)

NOTE:  For general assembly instructions refer to Sec-
tion 2.

1.

Install O-ring seal in bottom groove of pump body  
(Figure 8-79).

2.

Install driveshaft seal in pump body.

3.

Install rotor on thrust plate.

4.

Insert splined end of driveshaft through thrust plate and
rotor.

5.

Install retaining ring on driveshaft.

6.

Install dowel pins in pump body.

7.

Install driveshaft and rotor assembly in pump body.

CAUTION: To avoid damage to equipment, install pump
ring with arrow pointing up.

8.

Align dowel pins and small holes In pump ring.

9.

Install pump ring in pump body.

CAUTION: To avoid damage to equipment, install vanes
in rotor with rounded edges facing outward.

10. Install ten vanes in rotor.

CAUTION: To avoid damage to equipment, install pres-
sure plate with spring groove facing upward.

11. Install pressure plate on pump ring ensuring center

notches in pressure plate align with dowel pins.

Figure 8-79:   Pressure Plate and Rotor Installation

PRESSURE PLATE

VANES

ROTOR

DRIVESHAFT

DOWEL PIN

PUMP BODY

PUMP RING

RETAINING RING

THRUST PLATE

DOWEL PIN

O-RING SEAL

DRIVESHAFT SEAL

 4-1-00