992G Wheel Loader Machine Systems Caterpillar

Piston Pump (Fixed Displacement) - Assemble

Usage:

992G 7HR

Assembly Procedure

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Table 1
Required Tools
Tool	Part Number	Part Description	Qty
A	1U-7234	Feeler Gauge	1
B	5P-2986	Protective Plate	1
C		Gauge Bar	1
D	1P-1862	Pliers	1
E	1P-0510	Driver Gp	1
F	5P-2989	Retraction Plate	1
G	1P-0520	Driver Gp	1

Thoroughly clean all parts prior to assembly. Put a small amount of clean hydraulic oil on all internal parts during assembly.
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Illustration 1 g00508592
Heat bearing cone (18) to a maximum temperature of 120°C (248°F). Use insulated gloves to handle the bearing cone. Put the bearing cone in position on shaft (17).
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Illustration 2 g00508595
Lower the temperature of bearing cup (11). Install the bearing cup in the head of the pump. Make sure that the cup is firmly seated against the shoulder.
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Illustration 3 g00508598
Lower the temperature of bearing cup (31). Install the bearing cup in the pump body. Make sure that the cup is firmly seated against the shoulder.
Perform the following procedure only if the shaft, the bearings, the head or the pump body are being replaced. Otherwise, proceed to Step 6.
Note: Do not install the barrel assembly or the pistons for this procedure.
1. Heat bearing cone (13) to a maximum temperature of 120°C (248°F). Use insulated gloves to handle the bearing cone. Put the bearing cone in position on shaft (17).
  Note: Make sure that any rotating parts are lubricated before you rotate the shaft.
2. Install shaft (17) in the pump body.
3. Install the gasket, the head and the bolts on the pump body.
4. Put an 8S-2328 Dial Indicator Group in position in order to measure the axial movement of the shaft.
  Note: Use a torque wrench to turn the shaft. The torque that is needed to start the rotation must not be more than 55 N·m (40 lb ft). The torque that is needed to continue the rotation must not be more than 37 N·m (27 lb ft).
5. Rotate the shaft by 40 degrees in the clockwise direction and in the counterclockwise direction and zero the dial indicator.
6. Apply 5340 N (1200 lb) of force on the end of the shaft. Rotate the shaft by 40 degrees in the clockwise direction and in the counterclockwise direction. Record the reading from the dial indicator.
7. Remove the force on the end of the shaft. Rotate the shaft by 40 degrees in the clockwise direction and in the counterclockwise direction. The reading on the dial indicator must be zero.
  If the reading is not zero, repeat Steps 5.e through 5.g.
  Note: The reading on the dial indicator must not exceed 0.36 mm (0.014 inch). If the reading is less than 0.05 mm (0.002 inch), perform Steps 5.h through 5.l. If the reading exceeds 0.33 mm (0.013 inch), insert a 0.25 mm (0.010 inch) shim between the head and the cover and repeat Steps 5.e through 5.g.
8. Remove the head and insert a 0.25 mm (0.010 inch) shim between the head and the pump body. Install the head and tighten the bolts.
9. Rotate the shaft by 40 degrees in the clockwise direction and in the counterclockwise direction and zero the dial indicator.
10. Apply 5340 N (1200 lb) of force on the end of the shaft. Rotate the shaft by 40 degrees in the clockwise direction and in the counterclockwise direction. Record the reading from the dial indicator.
11. Remove the force on the end of the shaft. Rotate the shaft by 40 degrees in the clockwise direction and in the counterclockwise direction. The reading on the dial indicator must be zero.
  If the reading is not zero, repeat Steps 5.i through 5.k.
  Note: The reading on the dial indicator must be at least 0.28 mm (0.011 inch).
12. Remove the head, the shims, the gasket and the shaft from the pump body.
13. Remove bearing (13) from shaft (17).
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Illustration 5 g00508124

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Illustration 6 g00508123
Install spacer (24), spring (25) and spacer (26) in the barrel.
Place barrel assembly (15) in a suitable press, as shown. Put Tooling (B) on the face of the barrel. Put Tooling (E) between the press and spacer (26).
Use the press to compress spring (25). Use Tooling (D) to install snap ring (27).
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Illustration 7 g00508084
Install wear plate (23) in the cam plate. Make sure that the dowel in the cam is aligned with the dowel hole in the wear plate.
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Illustration 8 g00508077
Position pistons (19) on the wear plate in the correct sequence. Install retraction plate (22) over the pistons.
Put the original amount of shims and bearings (21) on the cam and install bolts (20).
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Illustration 9 g00508892
Use Tooling (A) to measure the clearance between the piston slippers and the wear plate.
The clearance between all of the piston slippers and the wear plate must be 0.090 ± 0.030 mm (0.0035 ± 0.0012 inch). Change the amount of shims, as needed.
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Illustration 10 g00508053
Put Tooling (B) against the face of the barrel. Place barrel assembly (15) on Tooling (F), as shown. Install the pistons and cam (16) in the barrel assembly. Make sure that the pistons are installed in the original locations.
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Illustration 11 g00508935
Install shaft (17), as shown.
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Illustration 12 g00508995
Install one 3/8 inch - 16 NC guide bolt (32) in the cam plate. The length of the guide bolt must be 203 mm (8 inch). Make sure that the dowel in the cam plate is aligned with the dowel hole in the pump body.
Use two persons to install the pump body over the shaft, as shown. The weight of the pump body is 36 kg (80 lb).
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Illustration 13 g00508325
Install O-ring seals (30) on the retainer. Use Tooling (G) to install lip seals (29). Make sure that the sealing lips of both lip seals are facing outward.
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Illustration 14 g00509002
Lubricate the seals on retainer (28) and install the retainer on the pump body, as shown. Remove guide bolt (32) and install three bolts (14) that secure the retainer to the pump body.
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Illustration 15 g00509066

Note: Do not scratch the polished surface of the barrel assembly. Pump efficiency will be reduced.
Tilt the pump on Tooling (F). Keep Tooling (F) flat on the face of the barrel. Use a hoist to carefully place the pump on a clean work bench, as shown. The weight of the pump is 141 kg (310 lb). Remove Tooling (F) and Tooling (B).
Heat bearing cone (13) to a maximum temperature of 120°C (248°F). Use insulated gloves to handle the bearing cone. Put the bearing cone in position on shaft (17). Make sure that the bearing cone is firmly seated against the shoulder.
Install the gasket on the pump body.
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Illustration 16 g00507887
Put a small amount of clean hydraulic oil on seal (12) and install the seal in the head.
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Illustration 17 g00507885
Turn the head onto the opposite side and install port plate (10) in the head. Make sure that the dowels on the head are aligned with the dowel holes in the port plate.
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Illustration 18 g00509073
Install two 1/2 inch - 13 NC guide bolts (3) through the bolt holes in the pump body. The length of the guide bolts must be 203 mm (8 inch). Put head (9) in position on the pump body, as shown.
Install two bolts (2) with flat washers in order to hold the head tight against the pump body.
Install original shims (8) and key (7) on the shaft.
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Illustration 19 g00509083
Install impeller (6) and nut (5) on the shaft. The torque for the nut is 150 ± 20 N·m (110 ± 15 lb ft).
Use Tooling (C) and Tooling (A) to check the clearance at 120 degree intervals around the impeller, as shown.
The clearance between the gauge bar and the impeller must be 0.44 ± 0.08 mm (0.017 ± 0.003 inch). Use more shims (8) behind the impeller, if necessary.
Remove two bolts (2).
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Illustration 20 g00507835

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Illustration 21 g00507834
Install the O-ring seal on cover (4). Install the cover on the head.
Install bolts (2) in order to secure cover (4) to the head. Remove two guide bolts (3) and install the remaining bolts.
Use a torque wrench to turn the shaft. The torque that is needed to start the rotation must not be more than 55 N·m (40 lb ft). The torque that is needed to continue the rotation must not be more than 37 N·m (27 lb ft).
Note: If the torque values are higher than the specifications, disassemble the pump and correct the problem.