Service Manual

HGM-H 7
TROUBLESHOOTING
In many cases, problems with a hydraulic sys-
tems are not related to a defective hydraulic
unit, but are caused by slipping drive belts,
partially engaged bypass valves, and loose or
damaged control linkages. Be sure to perform
all operational checks and adjustments outlined
in Service and Maintenance, before assuming
the hydraulic system is malfunctioning. The
table below provides a troubleshooting check-
list to help determine the cause of operational
problems.
WARNING
Do not attempt any servicing or ad-
justments with the engine running.
Use extreme caution while inspecting
the drive belt assembly and all vehicle
linkage!
Follow all safety procedures outlined in
the vehicle owner’s manual.
TROUBLESHOOTING CHECKLIST
Possible Cause Corrective Action
Unit Operates In One Direction Only
Control linkage bent or out of adjustment Repair or replace linkage on vehicle pump assembly, Page 8
Drive belt slipping or pulley damaged Repair or replace belt/pulley on vehicle pump assembly, Page 8
Vehicle Does Not Drive/Track Straight
Vehicle tires improperly inated Refer to vehicle manufacturer suggested tire pressure
Control linkage bent or out of adjustment Repair or replace linkage on vehicle pump assembly, Page 8
Drive belt slipping or pulley damaged Repair or replace belt/pulley on vehicle pump assembly, Page 8
Brake Partially Engaged Disengage Brake, Replace damaged brake components, Page 14
Unit Is Noisy
Oil level low or contaminated oil Fill to proper level or change oil, Page 8
Excessive loading Reduce vehicle loading, Page 8
Loose parts Repair or replace loose parts
Air trapped in hydraulic system Purge hydraulic system, Page 9
Brake Partially Engaged Disengage Brake, Replace damaged brake components, Page 14
Unit Has No/Low Power
Engine speed low Adjust to correct setting
Control linkage bent or out of adjustment Repair or replace linkage on vehicle pump assembly, Page 8
Drive belt slipping or pulley damaged Repair or replace belt/pulley on vehicle pump assembly, Page 8
Oil level low or contaminated oil Fill reservoir to proper level or change oil, Page 8
Excessive loading Reduce vehicle loading, Page 8
Air trapped in hydraulic system Purge hydraulic system, Page 9
Brake Partially Engaged Disengage Brake, Replace damaged brake components, Page 14
Unit Is Operating Hot
Debris buildup around transaxle Clean off debris, Page 8
Oil level low or contaminated oil Fill to proper level or change oil, Page 8
Excessive loading Reduce vehicle loading, Page 8
Air trapped in hydraulic system Purge hydraulic system, Page 9
Brake Partially Engaged Disengage Brake, Replace broken, missing or frozen return spring
Transaxle Leaks Oil
Damaged seals, housing, or gaskets Replace damaged components
Air trapped in hydraulic system Purge hydraulic system, Page 9