Hummer H1 (1992-1998). Manual - part 29
2-32. FUEL INJECTION PUMP REPAIR (Cont’d)
36. Using a micrometer, measure drive shaft (2) at point “A” to determine wear. Inspect drive shaft (2)
seal area for nicks, burrs, scratches, or damage. Replace drive shaft (2) if measurement at point “A”
is less than 0.305 in. (7.75 mm) or if any nicks, burrs, scratches, or damage is present.
37. Inspect dowel pin (1) in drive shaft (2) for damage. If damaged, replace dowel pin (1). Apply sealing
compound to replacement dowel pin (1).
CAUTION
Hydraulic head and rotor are matched sets and must be replaced
as an assembly or injection pump damage may result.
38. Inspect fittings (4) in hydraulic head (3) for damage. Replace hydraulic head (3) and rotor (13) if any
fittings (4) are damaged.
CAUTION
Do not handle precision ground surface of rotor to prevent
contamination.
39. Inspect hydraulic head (3) and rotor (13) for damage. Replace both if either is damaged.
40. Inspect charging ports (11) and discharge port (12) on rotor (13) for chipped edges. Replace hydraulic
head (3) and rotor (13) if any chipped edges are apparent.
41. Inspect rotor (13) for scratches. Replace hydraulic head (3) and rotor (13) if scratches are present.
Do not allow solvents to get on skin or clothing. Solvents can burn
easily and give off harmful vapors. Keep away from open fire and
use in a well-ventilated area. If solvent gets on skin or clothing,
wash immediately. Failure to follow these instructions could cause
injury or death.
NOTE
It maybe necessary to interchange or reverse plunger position
when installing plungers into rotor.
42, While holding rotor (13) under clean calibrating fluid, insert plungers (10) into bores of rotor (13).
With thumb and forefinger over roller shoe (9) slots, tilt from side to side to determine freedom
of movement. If the plungers (10) are sticking, but not visibly damaged, clean both plungers (10)
and bore with a soft brush and lacquer thinner or acetone. Check freedom of movement again.
If plungers (10) still stick, replace them with the next smaller size (“A” is the largest, “D” is the
smallest). If the smallest plungers (10) stick in rotor (13), replace hydraulic head (3) and rotor (13).
43. Inspect leaf spring contact area (14) and tang slot (7) on rotor (13) for excessive wear. Replace
hydraulic head (3) and rotor (13) if leaf spring contact area (14) or tang slot (7) are excessively worn.
44. Inspect cam rollers (8) for freedom of rotation in their roller shoes (9). Inspect cam rollers (8) and
roller shoes (9) for abrasive wear patterns. Replace cam rollers (8) and roller shoes (9) if cam
rollers (8) do not rotate freely or if either shows signs of abrasive wear patterns.
45. Inspect top edge of each roller shoe (9) for chipping or excessive wear. Replace cam rollers (8) and
roller shoes (9) if chipped or excessively worn.
46. Inspect leaf spring (6) for excessive wear. Replace leaf spring (6) if excessively worn.
47. Inspect leaf spring screw (5) for tightness in rotor (13). Replace leaf spring screw (5) if screw (5)
does not thread tightly into rotor (13).
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