Loader Bobcat 773. Manual - part 81

  1. Alternator belt is loose or damaged.

28. Worn valve and seats.

  2. Bad electrical connections.

29. Broken or worn piston rings.

  3. Faulty starter motor.

30. Worn valve stems or guides.

  4. Incorrect grade of oil.

31. Worn or damaged bearings.

  5. Low cranking speed.

32. Not enough oil in the crankcase.

  6. Fuel tank empty.

33. Switch/sensor is defective.

  7. Faulty stop control operation.

34. Oil pump worn.

  8. Plugged fuel line.

35. Relief valve is sticking open.

  9. Plugged fuel filter.

36. Relief valve is sticking closed.

10. Restriction in the air cleaner.

37. Broken relief valve spring.

11.

Air in the fuel system.

38. Faulty suction pipe.

12. Faulty fuel injection pump.

39. Plugged oil filter.

13. Faulty fuel injectors.

40. Piston seizure.

14. Broken injection pump drive.

41. Incorrect piston height.

15. Incorrect injection pump timing.

42. Faulty engine mounting.

16. Incorrect valve timing.

43. Incorrect flywheel alignment.

17. Poor compression.

44. Faulty thermostat.

18. Plugged fuel tank vent.

45. Restriction in water jacket.

19. Incorrect grade of fuel.

46. Loose alternator belt.

20. Exhaust pipe restriction.

47. Plugged radiator.

21. Cylinder head gasket leaking.

48. Faulty water pump.

22. Overheating.

49. Plugged breather pipe.

23. Cold running.

50. Damaged valve stem deflectors.

24. Incorrect tappet adjustment.

51. Coolant level to low.

25. Sticking valves.

52. Plugged oil pump pipe strainer.

26. Incorrect fuel lines.

53. Broken valve spring.

27. Worn cylinder bores.

Slow cranking speed.

1, 2, 3

Engine will not start.

2, 5, 6, 7, 8, 9, 11, 12, 13, 14, 15, 16, 19, 27, 28, 29

Difficult to start.

1, 2, 5, 7, 8, 9, 10, 11, 12, 13, 15, 16, 17, 18, 19, 20, 25, 27, 28, 29

No power for engine.

8, 9, 10, 11, 12, 13, 15, 16, 17, 18, 20, 21, 22, 23, 27, 28, 29

Engine is mis–firing.

8, 9, 11, 12, 13, 15, 16, 17, 21, 22, 24, 25, 26, 28

Too much fuel consumption.

10, 12, 13, 15, 16, 17, 19, 20, 21, 23, 24, 25, 27, 28, 29

Black exhaust.

10, 12, 13, 15, 16, 17, 19, 20, 21, 23, 24, 25, 27, 28, 29

Blue/white exhaust.

4, 10, 15, 16, 17, 21, 23, 27, 29, 30, 50

Low oil pressure.

4, 31, 32, 33, 34, 35, 37, 38, 39, 52

Engine knocking.

13, 15, 16, 19, 22, 24, 25, 27, 29, 31, 40, 41, 53

Engine running rough.

7, 8, 9, 10, 11, 12, 13, 17, 18, 22, 24, 25, 26, 29, 40, 53

Vibration.

12, 13, 17, 21, 22, 25, 26, 29, 40, 42, 43

High oil pressure warning.

4, 33, 36

Overheating.

10, 12, 13, 15, 16, 20, 21, 40, 44, 45, 46, 47, 48, 51

Too much crankcase pressure. 22, 27, 29, 30, 40, 49
Poor compression.

10, 16, 21, 24, 25, 27, 28, 29, 30, 41, 53

Start and stop.

9, 10, 11

TROUBLESHOOTING

Chart

The following troubleshooting chart is provided for assistance in locating and correcting problems which are most common.
Many of the recommended procedures must be done by authorized Bobcat Service Personnel only.

PROBLEM

CAUSE

KEY TO CORRECT THE CAUSE

773 BICS Loader

–7–3–

Service Manual

Raise the lift arms and install an approved lift arm device.
(See Page 1–1.)

Raise the operator cab. (See Page 1–1.)

Remove the two mounting bolts (Item 1) [A] and nuts from
the speed control mounting bracket.

Installation: Tighten the mounting bolts and nuts evenly
until the speed control lever moves back and forth at a
comfortable tension.

Pull the speed control away from the loader frame and
disconnect the speed control rod (Item 1) [B] from the
control.

Installation:  Be sure to install the control rod in the
bottom hole of the speed control.

Installation: Install the stop bracket (Item 1) [C] in the
same location. It is necessary for the front and rear stop
on the bracket to be located correctly.

Reverse the removal procedure to install the engine
speed control.

Disassembly

Loosen the two control lever mounting bolts (Item 2) [A]
and remove the mounting nuts (Item 2) [C].

Assembly: Do not lubricate the engine speed control.

Replace any worn or damaged parts if necessary.

ENGINE SPEED CONTROL

Removal And Installation

Never work on a machine with the lift arms up
unless the lift arms are secured by an approved
lift arm support device. Failure to use an
approved lift arm support device can allow the
lift arms or attachment to fall and cause injury
or death.

W–2059–0598

Revised Jan. 99

A

N–00810

1

1

2

C

P–04068

1

2

–7–4–

773 BICS Loader

Service Manual

B

P–04072

1

ENGINE MUFFLER

Removal And Installation

Open the rear door and raise the rear grill.

Remove the exhaust pipe clamp (Item 1) [A] from the
muffler (Item 2) [A].

Disconnect the exhaust pipe from the muffler.

Remove the left side mounting bolt (Item 3) [A] from the
muffler.

Remove the right side mounting bolt (Item 1) [B] from the
muffler.

Installation: Tighten the muffler mounting bolts to 25–28
ft.–lbs.  (34–38 Nm) torque.

Remove the muffler from the loader.

Reverse the removal procedure to install the engine
muffler.

A

P–03881

2

1

3

773 BICS Loader

–7–5–

Service Manual

B

P–03872

1

RADIATOR

Removal And Installation

Stop the engine and open the rear door.

Remove the rear grill. (See Page 5–1.)

Do not remove radiator cap when the engine is
hot. You can be seriously burned.

W–2070–1285

Open the drain valve (Item 1) [A] on the engine block and
drain the coolant into a container.

Loosen the radiator cap (Item 1) [B].

Disconnect the over flow hose (Item 2) [B] from the
radiator filler neck.

Raise the oil cooler and fasten out of the way.

Loosen the hose clamp (Item 1) [C]  from the left side
radiator hose and disconnect the hose from the radiator.

Remove the radiator mounting bolt (Item 2) [C].

Loosen the hose clamp (Item 1) [D] from the right side
radiator hose and disconnect the hose from the radiator.

Remove the radiator mounting bolt (Item 2) [D].

A

P–03971

1

C

P–04200

1

2

D

P–04199

1

2

–7–6–

773 BICS Loader

Service Manual

B

N–00833

2

1