994D Wheel Loader Machine System Caterpillar

Piston Pump (Brake) - Disassemble

Usage:

994D 3TZ

Disassembly Procedure

Show/hide table

Table 1
Required Tools
Tool	Part Number	Part Description	Qty
A	1P-1861	Retaining Ring Pliers	1
B	1P-0510	Driver Group	1
C	1P-1859	Retaining Ring Pliers	1
D	1P-1853	Retaining Ring Pliers	1

Start By:

Remove the piston pump. Refer to Disassembly and Assembly, "Piston Pump (Brake) - Remove".

Show/hide table

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.

Note: Cleanliness is an important factor. Before the disassembly procedure, the exterior of the component should be thoroughly cleaned. This will help to prevent dirt from entering the internal mechanism.

Show/hide table




Illustration 1	g00508973

Remove four bolts (1) that secure pressure compensator valve (2) to plate assembly (3). Remove pressure compensator valve (2), the O-ring seal, and the gasket from plate assembly (3). Remove four bolts (4) that secure plate assembly (3) to pump housing assembly (5). Remove plate assembly (3) and the gasket from pump housing assembly (5).

Show/hide table




Illustration 2	g00585001

Show/hide table

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.

Remove cap (15).
Remove spring cap (14) from pressure compensator valve (2).
Remove spring cap (9) and O-ring seal (10).
Remove jam nut (11) and hex socket setscrew (12).
Remove O-ring seal (8) from spring cap (14).
Remove cap (6) and spring (7).
Remove O-ring plug (13) and the O-ring seal from pressure compensator valve (2).
Show/hide table

Illustration 3 g00585575
Remove control piston (16) from plate assembly (3).
Show/hide table

Illustration 4 g00585579
Remove needle bearing (17) and pin (18) from plate assembly (3).
Show/hide table

Illustration 5 g00585582
Remove pump rotating group (19) from pump housing assembly (5).
Show/hide table

Illustration 6 g00585614

Show/hide table

Illustration 7 g00585618
Remove spherical washer (22) from retraction plate (20).
Note: Identify the location of the pistons and the corresponding bores for installation purposes.
Remove retraction plate (20) with nine pistons (21) from barrel (23).
Remove nine pistons (21) from retraction plate (20).
Show/hide table

Illustration 8 g00585626

Show/hide table

Illustration 9 g00585628

Use a suitable press and Tooling (B) in order to hold spring (28) in compression.

Show/hide table

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.

Use Tool (A) in order to remove retaining ring (24).
Slowly release the compression on spring (28).
Remove the following item from barrel (23): spring (28), two washers (27), retainer (26) and three pins (25).
Show/hide table

Illustration 10 g00585584
Use Tooling (C) (not shown) to remove retaining ring (30) from pump housing assembly (5). Remove shaft (29) from pump housing assembly (5).
Show/hide table

Illustration 11 g00585585
Remove shaft seal (32) and washer (31) from pump shaft (29).
Show/hide table

Illustration 12 g00585588
Use Tooling (D) (not shown) to remove two retaining rings (34) from pump shaft (29). Remove two thrust bearing races (33) and thrust bearing (35) from pump shaft (29).
Show/hide table

Illustration 13 g00585590
Use Tooling (C) (not shown) to remove pin retainer (38) from pump housing assembly (5). Remove trunnion cover (40), O-ring seal (37), needle bearing (39) and inner race (36) from pump housing assembly (5). Repeat the procedure for the other side of the pump housing assembly.
Show/hide table

Illustration 14 g00585592
Remove swashplate (41) from pump housing assembly (5).
Show/hide table

Illustration 15 g00585593
Remove the following items from pump housing assembly (5): spring collar (42), the spring pin, the pivot button and spring (43)
Show/hide table

Illustration 16 g00617242
Turn over the housing assembly. Use Tooling (B) to remove needle bearing (44) (not shown) from pump housing assembly (5).