Loader Bobcat 773. Manual - part 44

HYDROSTATIC MOTOR 30 SERIES (Cont’d)

Disassembly (S/N 509639899 & Above & S/N
509616505 & Above) (Cont’d)

Remove the spring seat (Item 1) [A], spring (Item 2) [A]
and poppet (Item 3) [A].

Remove the low pressure relief valve plug from the side
of the end cover [B].

Remove the spring (Item 1) [C] and poppet (Item 2)
[C]from the end cover (Item 3) [C].

NOTE: The relief pressure is factory set and must

not be changed. Shims may or may not have
been used at the factory for setting the
pressure. If shims are present, make sure
they are reinstalled during assembly.

The low pressure relief valve is made up of the poppet
(Item 1) [D], the spring (Item 2) [D] and the plug assembly
(Item 3) [D].

A

N–00637

1

2

3

C

N–00640

3

2

1

D

N–00641

3

2

1

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B

N–00639

HYDROSTATIC MOTOR 30 SERIES (Cont’d)

Assembly (S/N 509639899 & Above & S/N 509616505
& Above)

When repairing hydrostatic and hydraulic
systems, clean the work area before
disassembly and keep all parts clean. Always
use caps and plugs on hoses, tubelines and
ports to keep dirt out. Dirt can quickly damage
the system.

I–2003–0888

Prior to assembly:

Clean all parts with solvent and dry with compressed air.

Put grease on O–rings.

Lubricate parts with oil.

Install the poppet (Item 1) [A] and spring (Item 2) [A] in
the low pressure relief port in the end cover.

Install the new O–ring on the plug and tighten to 300
in.–lbs. (34 Nm) torque [B].

Install the poppet (Item 1) [C], the spring (Item 2) [C] and
the spring seat (Item 3) [C] in the end cover.

NOTE: The tapered end of the poppet must face

towards the shuttle valve.

Install a new O–ring on the plug [D] and tighten to 260
in.–lbs. (41 Nm) torque.

NOTE: Always use new O–rings and seals when

assembling the motor. Put a small amount of
grease on all the O–rings and seals for easier
installation.

A

N–00642

2

1

C

N–00644

2

3

1

D

N–00646

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B

N–00643

HYDROSTATIC MOTOR 30 SERIES (Cont’d)

Assembly (S/N 509639899 & Above & S/N 509616505
& Above) (Cont’d)

Install the shuttle valve (Item 1) [A], poppet (Item 2) [A],
spring (Item 3) [A] and spring seat (Item 4) [A] in the port
hole in the end cap.

NOTE: The tapered end of the poppet must face

towards the shuttle valve.

Install the square cut seal (Item 1) [B] and small O–ring
(Item 2) [B] in the end cover.

Mark the case drain port location on the outside of the end
cover for ease of assembly [C].

Align the case drain ports in the valve plate with the case
drain port in the end cover [D].

A

N–00647

3

4

2

1

C

N–00649

D

N–00650

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773 BICS Loader

Service Manual

B

N–00648

1

2

HYDROSTATIC MOTOR 30 SERIES (Cont’d)

Assembly (S/N 509639899 & Above & S/N 509616505
& Above) (Cont’d)

Install the large square cut seal (Item 1) [A] in gerolor
assembly.

Mark the case drain port location on the outside edge of
the valve plate as shown [B].

Install the gerolor assembly (Item 1) [C] by aligning the
case drain hole with the case drain hole in the valve plate.

Install the square cut seal (Item 1) [D] in the gerolor outer
ring.

A

N–00651

1

C

N–00653

1

D

N–00654

1

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B

N–00652