Loader Bobcat 773. Manual - part 46

HYDROSTATIC PUMP (Cont’d)

Removal And Installation (Cont’d)

Installation: Install the key in the hydrostatic pump shaft
(Item 1) [A] before installing the pump drive pulley.

Hold the nut (Item 1) [B] on the two hydrostatic pump
mounting bolts (Item 2) [A].

Remove the two hydrostatic pump mounting bolts (Item
2) [A] from the pump and drive belt housing.

Installation: Tighten the pump mounting bolts to 65–70
ft.–lbs. (88–95 Nm) torque.

Reverse the removal procedure to install the hydrostatic
pump assembly.

Always clean up spilled fuel or oil. Keep heat,
flames, sparks or lighted tobacco away from
fuel and oil. Failure to use care around
combustibles can cause explosion or fire
which can result in injury or death.

W–2103–1285

A

P–04238

2

1

–3–36–

773 BICS Loader

Service Manual

B

P–04277

1

D–01929

1

2

3

4

5

6

7

8

13

10

9

21

17

18

14

12

9

34

35

36

39

38

41

45

42

29

27

26

12

23

24

22

49

43

47

25

48

25

23

26

24

22

16

16

15

15

13

19

20

17

18

11

14

40

45

32

30

46

44

20

23

22

24

27

33

21

21

28

29

25

26

32

31

25

28

23

26

22

38

37

34

36

9

10

15

11

14

17

21

18

18

17

9

51

52

6

5

1

16

16

35

24

30

1514

D–01979

HYDROSTATIC PUMP (Cont’d)

Identification
MODEL: 773

50

–3–38–

773 BICS Loader

Service Manual

HYDROSTATIC PUMP (Cont’d)

Identification (Cont’d)

Ref.

Description

Ref.

Description

  1.

SNAP RING

28.

PLUG

  2.

ADAPTER

29.

BOLT

  3.

SEAL

30.

RELIEF/REPLENISHING VALVE

  4.

O–RING

31.

END CAP

  5.

SNAP RING

32.

BEARING

  6.

BEARING

33.

BOLT

  7.

KEY

34.

SWASHPLATE

  8.

SHAFT

35.

THRUST PLATE

  9.

BOLT

36.

BLOCK ASSY.

10.

COVER

37.

VALVE PLATE

11.

SEAL

38.

PIN

12.

COVER

39.

VALVE PLAT

13.

PLUG

40.

PLUG

14.

QUAD RING

41.

O–RING

15.

SPACER

42.

SHIMS

16.

SHIMS (not used on later pumps)

43.

SPRING

17.

RACE

44.

CHARGE RELIEF

18.

BEARING

45.

PLUG

19.

HOUSING

46.

O–RING

20.

GASKET

47.

O–RING

21.

PIN

48.

END CAP

22.

PLUG

49.

O–RING

23.

O–RING

50.

COUPLING

24.

O–RING

51.

HOUSING

25.

SPRING

52.

SHAFT

26.

SNAP RING

27.

REPLENISHING VALVE (S/N 509641106
& Below, S/N 509616589 & Below)
RELIEF/REPLENISHING VALVE (S/N 509641107
& Above, S/N 509616590 & Above)

MODEL: 773

773 BICS Loader

–3–39–

Service Manual

HYDROSTATIC PUMP (Cont’d)

Disassembly And Assembly

NOTE: Keep the two pump sections separate during

disassembly and assembly.

Loosen the charge relief valve plug [A].

Assemble: Always use a new O–ring. Tighten the plug to
30–50 ft.–lbs. (41–68 Nm) torque.

Remove the plug, spring and poppet [B].

There are several different thickness of the shims (Item
1) [C] and are used to adjust the charge pressure.

NOTE: Photo’s may be different but the procedure is

the same for all models.

NOTE: S/N 509641107 & Above and S/N 509616590 &

Above now use relief/replenishing valves
(Item 1) [D]. The relief valve limits the
pressure in the motor drive circuit when
operating in reverse.

NOTE: The relief valve on the top of the pump is for

the reverse circuit, the bottom relief valve on
the pump is for the forward circuit and is set
at 5000 PSI.

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

Loosen the replenishing valve plug [D].

Assemble: Always use a new O–ring. Tighten the plug to
30–50 ft.–lbs. (41–68 Nm) torque.

NOTE: 0.010 inch (0,254 mm) is 8 PSI (55.16 kPa)

increase in pressure.

A

CD–10745

C

N–00961

1

D

CD–10748

1

–3–40–

773 BICS Loader

Service Manual

B

CD–10746