Pump Rebuild - Komatsu 930E-2 Shop Manual

PUMP REBUILD

Be certain to bleed steering accumulators to re-
lieve hydraulic pressure and to relieve pump outlet
grease pressure before removing any hoses or
fittings.
Disassembly
1. Remove the four socket head screws (33, Figure
3-9) and separate the manifold (37) from the
hydraulic motor (42).
2. Remove pipe plug (45) and drain the crankcase
oil from pump housing (46).
3. Remove the six screws (29) and remove the
housing cover (30) and cover gasket (31).
4. Remove retaining ring (57) and pull the shovel
plug (56) from the housing tube (55).
5. Remove two socket head screws (44) and sepa-
rate hydraulic motor (42) from the pump housing
(46).
6. Remove two outlet pin nuts (50) from pump hous-
ing.
7. Remove the pump subassembly (1 through 28)
from the pump housing. Pushing the subassem-
bly up with a .75 in. (19 mm) diameter wooden or
plastic rod against the check seat housing (28) is
helpful.
8. Remove the housing tube (55) from the pump
housing by inserting a .75 in. (19 mm) diameter
rod through the inlet holes at the bottom of the
housing tube and unscrewing it.
9. Remove the bronze bearing (51), O-ring (52),
backup washer (53), and O-ring (54) from the
housing tube.
10. Remove the crankrod assembly (1 through 8) from
the pump by unscrewing the button head screws
(12) and then pulling out the wrist pin bushings
(13).
11. Remove the check seat housing (28) from the
reciprocating tube (21).
Note: There is a 3/8 in. allen head socket in the throat
of the check seat housing to facilitate removal.
12. Unscrew the wrist pin anchor (14) from the recip-
rocating tube (21) and pull the plunger assembly
(9 through 20) from the tube.
P3- 10
13. Using a .50 in. (13 mm) diameter wooden or plastic
rod, push the cup seal (22) and the pump cylinder
(24) from the reciprocating tube.
14. Remove the pump plunger (20) from the plunger
link rod (17). (A spanner wrench, which uses the
holes in the the pump plunger, is required.)
15. Unscrew the plunger link rod (17) from the plunger
tube (11) and slide off the cup seal (16) backup
washer (15) and wrist pin anchor (14).
16. Unscrew the plunger tube (11) from the outlet pin
(9).
17. To dismantle the crankrod assembly (1 through 8),
remove flat head screws (1) and the inner and
outer weights (2 & 3).
18. Remove the small retaining rings (6) and press the
crank eccentric (7) out of the ball bearing (8). Be
sure to support the ball bearing on the inner race.
Cleaning and Inspection
1. Discard all seals and gaskets. Repair kits are
available containing all the necessary seals and
gaskets for reassembly. Refer to the appropriate
truck parts book.
2. Clean and inspect the following parts. Replace if
excessive wear is evident:
Automatic Lubrication System
Ball bearing (8)
Crank eccentric (7)
Crankrod (5)
Wrist pin bushings (13)
Plunger tube (11)
Pump plunger & upper check parts (20, 19 &
18)
Pump cylinder (24)
Check seat housing/lower check ball (28, 26)
Upper bronze bushing (51)
Housing tube (55)
Shovel plug (56)
Reciprocating tube (21)
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