Hummer H1 (1992-1998). Manual - part 30

2-32. FUEL INJECTION PUMP REPAIR (Cont’d)

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CAUTION

Do not handle precision ground surface of rotor to avoid
contamination.
Handle all parts carefully with clean hands wet with calibrating
fluid to avoid contamination.

6. Mount governor weight support in vise and rinse rotor (1) in calibrating fluid and install in support.

NOTE

. 

Delivery valves are available in standard and oversize. If

replacing delivery valve, check for marking “OS” on side of rotor.
If “OS” marking is present, oversize delivery valve must be used.

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Oversize delivery valves have a black marking at the base of

delivery valve.

7. Install delivery valve (2) in rotor (1).
8. Install valve spring (3) and valve stop (4) in rotor (1).

CAUTION

Excessive tightening of stop plug will cause seizure of hydraulic
head and rotor.

9. Using 5/32-in. hex head driver, install stop plug (5) in rotor (1) and tighten to 85-90 lb-in. (10 N•m).

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2-32. FUEL INJECTION PUMP REPAIR (Cont’d)

10. Install leaf spring (9) and adjusting screw (10) on rotor (1).
11. Remove rotor (1) from governor weight support and submerge in calibrating fluid.

NOTE

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Plungers of any given nominal diameter are graded in four select

fit sizes: A, B, C, and D. The rotor is etched with the letter indi-
cating bore size. This mark is found on the base of the rotor.

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If plunger replacement is required, check the size designation on

the rotor and use the plunger of corresponding part number as
indicated by letter designation on rotor.

12. Install two plungers (8) in rotor (1).

13. Assemble two cam roller shoes (7), and cam rollers (6), and install in rotor (1).

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 2-32. FUEL INJECTION PUMP REPAIR [Cont’d)

14.
15.

Install roller-to-roller setting tool in soft-jaw vise.

Install roller (1) in roller-broiler setting  tool.

16.

17.

18.

19.

20.

 21.

22.

23.
24.
25.

WARNING

Always wear eyeshields when using compressed air. Failure to
wear eyeshields may result in eye injury.

Apply compressed air regulated to 40-100 psi (276-689 kPa) to roller-broiler setting tool.

NOTE

Increase roller-to-roller dimension 0.006 in. (0.152 mm) if using

oversize cam ring.

Measure roller-to-roller dimension and compare to pump specification 1.981 in. (50.31 mm).

NOTE

Roller-to-roller dimension is a completely accurate maximum fuel
adjustment and should not differ from pump specification.

Turn leaf spring adjusting screw (2) clockwise to increase or counterclockwise to decrease roller-
to-roller dimension.
Rotate rotor (1) until one cam roller (3) aligns with roller-to-roller setting tool dial indicator plunger.
Loosen indicator dial retaining screw and set preload by sliding indicator down until plunger
depresses on cam roller (3) 0.015 in. (0.381 mm). Tighten screw.
Rotate dial on indicator to “zero” indicator on high point of cam roller (3).

NOTE

If cam roller centrality is greater than 0.008 in. (0.203 mm),
cam shoes can be interchanged or replaced to achieve tolerance.
Centrality must be rechecked after each time components are
changed.

Measure cam roller centrality by rotating rotor (1) in either direction until high point of other
cam roller (3) depressed dial indicator plunger. Indicator reading should be 0.000 in. to 0.008 in.
(0.000 to 0.203 mm).
Rinse hydraulic head (4) with calibrating fluid.

Remove rotor (1) from roller-to-roller setting tool and rinse with calibrating fluid.
Install rotor (1) in hydraulic head (4).

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2-32. FUEL INJECTION PUMP REPAIR (Cont’d)

26. Install head seal (5) on rotor (4).

27. Install cam ring (8) on hydraulic head (4) with directional arrow on ring showing counterclockwise

rotation of pump rotor (1).

28. Install weight retainer (7) on rotor (1), align with check ball, and secure with snapring (6).

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