992G Wheel Loader Machine Systems Caterpillar

Piston Pump (Fixed Displacement) - Disassemble

Usage:

992G 7HR

Disassembly Procedure

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Table 1
Required Tools
Tool	Part Number	Part Description	Qty
A	5F-7345	Screw	1
	8B-7554	Bearing Cup Puller	1
	7S-7786	Puller Leg	2
	8B-7560	Step Plate	1
B	5P-2986	Protective Plate	1
C	8B-7548	Push-Puller Tool Group	1
	8H-0663	Bearing Puller	1
	8B-7560	Step Plate	1
D	1P-1862	Pliers	1
E	1P-0510	Driver Group	1
F	5P-2989	Retraction Plate	1
G	1P-0520	Driver Group	1

Start By:

Remove the fixed displacement pump. Refer to Disassembly and Assembly, "Piston Pump (Fixed Displacement) - Remove".

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NOTICE

Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting, and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids. Refer to Special Publication, NENG2500, "Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Cat^® products. Dispose of all fluids according to local regulations and mandates.

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Illustration 1	g00507829

Note: The pump that is shown in the following illustrations should have mounting flange (1). Otherwise, the pumps are identical.

Thoroughly clean the outside of the piston pump prior to disassembly.
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Illustration 2 g00507834

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Illustration 3 g00507835
Use a hoist to carefully place the pump on a clean work bench. The weight of the pump is 141 kg (310 lb).
Remove two bolts (2) from the cover and install two 1/2 inch - 13 NC guide bolts (3). The length of the guide bolts should be 203 mm (8 inch).
Remove the remaining bolts and cover (4) from the head of the pump. Remove the O-ring seal from the cover.
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Illustration 4 g00507845
Remove nut (5) and impeller (6) from the shaft.
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Illustration 5 g00507866
Remove key (7) and shims (8) from the shaft.
Remove head (9) from the pump body.
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Illustration 6 g00507885

Note: Do not scratch the polished surface of the port plate or of the barrel assembly. Pump efficiency will be reduced.
Remove port plate (10) from the head.
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Illustration 7 g00507886
Use Tooling (A) to remove bearing cup (11) from the head.
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Illustration 8 g00507887
Turn the head onto the opposite side and remove seal (12).
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Illustration 9 g00507954
Install Tooling (B) against the face of the barrel assembly. Use Tooling (C) to remove bearing cone (13).
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Illustration 10 g00507958
Remove three bolts (14) that hold the cam in position.
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Illustration 11 g00508014

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Illustration 12 g00508018
Remove barrel assembly (15), shaft (17) and cam (16) from the pump body as a unit. The weight of the assembly is 41 kg (90 lb).
Remove shaft (17) from the assembly.
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Illustration 13 g00508051
Place shaft (17) in a suitable press, as shown. Remove bearing cone (18).
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Illustration 14 g00508053

Note: Do not scratch the polished surface of the pistons. Pump efficiency will be reduced. Also, make sure that the pistons remain in the barrel assembly during removal. Each piston must be reinstalled in the same bore during assembly.
Make sure that Tooling (B) is in position against the barrel. Place the barrel assembly in a vertical position on Tooling (F).
Put identification marks on each piston and on the barrel for assembly purposes. Remove cam (16) and the pistons from barrel assembly (15).
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Illustration 15 g00508077
Remove eight bolts (20), the washers, bearings (21) and the shims from the cam.
Remove restriction plate (22) and pistons (19) from the cam.
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Illustration 16 g00508084

Remove wear plate (23) from the cam.

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Illustration 17	g00508123

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Illustration 18	g00508124

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Personal injury can result from being struck by parts propelled by a released spring force.
Make sure to wear all necessary protective equipment.

Follow the recommended procedure and use all recommended tooling to release the spring force.

Place barrel assembly (15) in a suitable press, as shown. Put Tooling (B) on the face of the barrel. Put Tooling (E) between the head of the press and spacer (26).
Push down on spring (25) in order to release the spring force against snap ring (27). Use Tooling (D) to remove snap ring (27). Then, slowly release the spring force.
Remove spacer (26), spring (25) and spacer (24) from the barrel.
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Illustration 19 g00508147
Strike retainer (28) lightly with a hammer in order to remove the retainer from the pump body.
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Illustration 20 g00508325
Remove two lip seals (29) from the inside of the retainer. Remove two O-ring seals (30) from the outside of the retainer.
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Illustration 21 g00508400
Use Tooling (G) to remove bearing cup (31) from the pump body.