Troubleshoot Hydraulic System - Yale A7S1 Service Manual

8000 YRM 2199
1. HOSE CLAMP
2. PUMP SUCTION PIPE
3. PUMP SUCTION FITTING
4. 0-RING 35×3.5
5. GEAR PUMP
6. 0-RING 80×3.55
7. WASHER 10
8. WASHER 10
9. BOLT M10×35
10. 0-RING 22×2.4
11. PUMP OUTLET FITTING
12. VALVE H.P. HOSE
13. 0-RING 18×2.4
14. STEERING CYLINDER
CONNECTOR
15. STEERING CYLINDER H.P.
HOSE I
16. STEERING CYLINDER H.P.
HOSE II
17. ORBITAL PIPE

TROUBLESHOOT HYDRAULIC SYSTEM

Problem
Fluid Level Low
Failure of Gear Pump
for Supercharge
Noise of Gear Pump
Loud
Fluid Leak with Pump
Legend for Figure 57.
18. HOOP D25
19. ORBITAL PIPE CONNECTOR
20. ORBITAL CONNECTOR I
21. ORBITAL CONNECTOR II
22. ORBITAL
23. MULTI-CHANNEL VALVE-
HOSE II
24. CONNECTOR
25. VALVE INLET CONNECTOR
26. 0-RING 24×2.4
27. MULTI-CHANNEL VALVE
28. MULTI-CHANNEL VALVE-TILT
CYLINDER CONNECTOR
29. RETURN OIL HOSE
30. TILT CYLINDER PIPE I
31. TILT CYLINDER PIPE II
32. CLIP I
33. CLIP II
34. TILT CYLINDER HOSE
(FRONT)
Cause
Fluid level in tank is at low end
Fluid suction side pipeline or filter blocked
Bearings are worn, and bearing seal rings
are at fault.
Overflow valve misadjusted
Air blended into pump
Fluid suction hose twisted, or cavity blocked
by filter
Air pulled inside due to loosening of fluid
suction side joint
Excessive fluid viscosity
Air bubble present in hydraulic fluid
Seal and seal ring of pump at fault
Sliding face worn (for internal leak to be
increased)
35. TILT CYLINDER CONNECTOR
36. 0-RING 16×2.4
37. BOLT M6×25
38. WASHER 6
39. WASHER 6
40. NUT M6
41. BOLT M6×12
42. CLIP
43. BOLT M8×20
44. WASHER 8
45. NUT M8
46. CLAMP PLATE
47. CLAMP
48. CLIP
49. CABLE TIE
50. DIVERTER CONNECTOR
51. DIVERTER CONNECTOR
Solution
Fill fluid to the specified level
Clean or replace fluid if dirty
Replace
Raise pressure gauge
Tighten joint at suction pipe side
Add fluid into tank
Check pump seal
Run pump until there are no more air
bubbles in fuel tank
Clean filter and adjust hose
Tighten each joint
Use proper viscosity fluid
Do not operate until fluid temperature is
normal
Check for cause of air bubble
Replace
Hydraulic System
59