990K Wheel Loader and 844K Wheel Dozer Machine Systems Caterpillar

Piston Pump (Brake, Steering) - Assemble

Usage:

990K A9P

Assembly Procedure

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Table 1
Required Tools
Tool	Part Number	Part Description	Qty
A	437-3776	Fixture As.	1
	1U-9127⁽¹⁾	Adapter Plate	1
	1U-5750	Engine Stand	1
B	1P-0510	Driver Gp	1
B	5P-8244	Hard Washer	2
C	8H-0663	Bearing Puller Gp	1
D	-	Loctite 243	-
E	6V-2055	Grease	1

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⁽¹⁾	Part of the Hydraulic Test Bench Tooling.

Note: Lubricate all parts with clean hydraulic oil during assembly.

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Illustration 1	g06225190

Lower the temperature of bearing cup (42). Install bearing cup (42) into pump body (1).
Install lip seal (41) and retaining ring (40).
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Illustration 2 g06225191
Raise the temperature of bearing cone (39). Install bearing cone (39) onto shaft assembly (21). Make sure that the bearing cone is seated properly.
Refer to "Setting Bearing Preload" before continuing with assembly.
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Illustration 3 g06225187
Install bearings (38). Install new screws (36). Tighten screws (36) to a torque of 5 ± 0.5 N·m (44 ± 4 lb in).
Note: New screws (36) must have a threadlocker, if not apply Tooling (D) to the threads.
Install shaft assembly (21) and spring (37) into pump body (1).
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Illustration 4 g06225186
Install swashplate (35) into pump body (1) by lowering the side marked (X) last.
Note: Caution must be used when you install the swashplate. Swashplate (35) must be properly engaged onto the spring.
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Illustration 5 g06225185
Install plug (34) into pump body (1).
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Illustration 6 g06225183

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Improper assembly of parts that are spring loaded can cause bodily injury.
To prevent possible injury, follow the established assembly procedure and wear protective equipment.
Install plugs (33) and the O-ring seals into pump body (1).
Apply Tooling (D) onto the threads of plug (32). and the O-ring seal. Install plug (32) and the O-ring seal.
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Illustration 7 g06225182
Apply Tooling (E) onto pins (29). Install pins (29), spacer (30), and spring (31) into barrel assembly (24).
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Illustration 8 g06225181

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Improper assembly of parts that are spring loaded can cause bodily injury.
To prevent possible injury, follow the established assembly procedure and wear protective equipment.
Use Tooling (B), Tooling (C), and a suitable press to compress the barrel spring.
Install retaining ring (28) into barrel assembly (24).
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Illustration 9 g06225192
Ensure that pins (29) are at the same height, if not repeat Steps 11 through 13.
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Illustration 10 g06225157
Install guide (26), piston retainer (27), and pistons (25) into barrel assembly (24).
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Illustration 11 g06225193
Rotate pump body (1) and install barrel assembly (24).
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Illustration 12 g06225006
Install shim (22) onto shaft assembly (21).
Install O-ring seal (23) onto pump body (1).
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Illustration 13 g06225002
Install bearing cone (20) onto shaft assembly (21).
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Illustration 14 g06224997
Lower the temperature of bearing cup (19). Install bearing cup (19) into pump flange (16).
Install O-ring seal (17) and control plate (18) onto pump flange (16).
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Illustration 15 g06224976

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Improper assembly of parts that are spring loaded can cause bodily injury.
To prevent possible injury, follow the established assembly procedure and wear protective equipment.
Install pump flange (16) and bolts (15) onto pump body (1). Tighten bolts (15) to a torque of 37 ± 3 N·m (327 ± 26 lb in).
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Illustration 16 g06224971
Install O-ring seal (13) and coupler (14) onto the piston pump.
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Illustration 17 g06225139
Install O-ring seal (12) and backup ring (11) onto adjustment screw (8).
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Illustration 18 g06225194
Install adjustment screw (8) in the direction shown.
Install plate (10) into plug (6).
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Illustration 19 g06225127
Install nut (9).
Set adjustment screw (8) to the height from plug (6) before disassembly.
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Illustration 20 g06225130
Install O-ring seal (7) onto plug (6).
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Illustration 21 g06225123

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Improper assembly of parts that are spring loaded can cause bodily injury.
To prevent possible injury, follow the established assembly procedure and wear protective equipment.
Install plug (6) into valve assembly (3).
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Illustration 22 g06225119
Install gasket (4), plug (5), and the seal.
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Illustration 23 g06224966
Install valve assembly (3) and bolts (2). Tighten bolts (2) to a torque of 15.5 ± 1.5 N·m (135 ± 10 lb in).
Remove pump body (1) from Tooling (A) or a suitable workbench.

End By:

Install the piston pump.

Setting Bearing Preload

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Illustration 24	g03642164

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Illustration 25	g03640681

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Illustration 26	g03642166

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Illustration 27	g03642169

Set bearing preload before you install the rotating group. The bearing preload should be 0.00 to 0.05 mm (0.000 to 0.002 inch) .
Note: The bearing cup must be installed to check the bearing preload.
1. Do not install shim (10). Install bearing cone (7) onto shaft (8). Assemble the pump without shim (10) to check the preload of bearing cone (7).
2. Install port block (2) on pump housing (1). Install bolts (3).
3. Install Tooling (D) onto the pump housing. Use the dial indicator to determine the end play of shaft (8). Be sure that you move shaft (8) completely in both directions. Use appropriate tools to move shaft (8).
4. The thickness of shim (10) found in Step 17 should equal the end play measurement plus 0.0508 mm (0.00200 inch). For example, if the end play is 2.1590 mm (0.08500 inch) then the shim thickness should be 2.2098 mm (0.08700 inch).
5. Record the measurement.
6. If necessary, grind the shim to the determined measurement.
Do not install shim (10). Install bearing cone (7) onto shaft (8). Assemble the pump without shim (10) to check the preload of bearing cone (7).
Install port block (2) on pump housing (1). Install bolts (3).
Install Tooling (D) onto the pump housing. Use the dial indicator to determine the end play of shaft (8). Be sure that you move shaft (8) completely in both directions. Use appropriate tools to move shaft (8).
The thickness of shim (10) found in Step 17 should equal the end play measurement plus 0.0508 mm (0.00200 inch). For example, if the end play is 2.1590 mm (0.08500 inch) then the shim thickness should be 2.2098 mm (0.08700 inch).
Record the measurement.
If necessary, grind the shim to the determined measurement.