5-5
HYDRAULIC SYSTEM
Most hydraulic system failures follow the same pattern: a gradual or sudden loss of pressure or flow
with a resulting loss of cylinder or motor power. Any one of the system’s components may be at fault.
By following step-by-step procedures, the trouble can be located in a short time.
SYMPTOM
PROBLEM: REMEDY
SYSTEM INOPERATIVE
Not enough oil in system:
fill, check for leaks.
Wrong oil in system:
change oil, see specifications.
Filter dirty or clogged:
drain oil and replace filter.
Hydraulic lines dirty or collapsed:
clean or replace as neces-
sary.
Air leaks in pump suction line:
repair or replace as neces-
sary.
Worn or dirty pump: clean, repair or replace.
Check for con-
taminated oil. Drain and flush.
Badly worn components:
examine for internal leakage. Re-
place faulty components. Check for cause of wear.
Leakage:
check all components, and relief valve for proper set-
tings.
Excessive load:
check unit specifications for load limits.
Slipping or broken pump drive:
repair or replace couplings.
Check for alignment.
SYSTEM OPERATES ERRATIC-
ALLY
Air in the system:
check suction side of system for leaks. Re-
pair leaks.
Cold oil:
allow ample warm-up time. Use proper weight oil
for operating temperature.
Dirty or damaged components:
clean or repair as needed.
Restriction in filters or lines:
clean and/or replace filter or
lines.
Not enough oil in system:
fill and check for leaks.
SYSTEM OPERATES SLOWLY
Oil viscosity too high, or “cold oil”.
Allow oil to warm up
before operating.
Low pump drive speed:
increase engine speed (check pump
owners manual for specifications).
Low oil level:
check reservoir and add oil as necessary.
Air in system:
check suction side for leaks. Repair leaks.
Badly worn pump, valves, cylinders, etc.:
repair or replace
faulty component(s) as necessary.
Restrictions in lines or filter:
clean and/or replace filter or
lines.
Improper adjustments:
check orifices, relief valves, etc.
Adjust as necessary.
Oil leaks:
tighten fittings. Replace seals, gaskets and dam-
aged lines.
5-7
Summary of Contents for 900B Series
Page 8: ......
Page 12: ......
Page 52: ...4 12 Figure 4 5 Wired Remote Control Diagrams...
Page 53: ...4 13 Figure 4 6 Tandem Triple Axle Air Ride Suspension Figure 4 7 Air Ride Height Adjustment...
Page 56: ...4 16 Figure 4 9 Checking Axle Alignment Figure 4 10 Examples of Camber...
Page 61: ...4 21 Figure 4 13 Axle and Brake Assembly...
Page 71: ...4 31 Figure 4 21 Crank Landing Gear Assembly...
Page 81: ...5 9 NOTES...
Page 82: ......