Service Manual

HY13-1521-M2/US Service Manual
General Information Series HB Hydrostatic Transmission
Troubleshooting Checklist
Trouble Cause Remedy
1. Fitting loose, worn or
damaged.
Check & replace damaged fittings or
“O” rings. Torque to manufacturers
specifications.
Oil Leakage
2. Oil seals deteriorated
by excess heat.
Replace oil seals by disassembling
unit.
1. Debris buildup Remove debris
2. Cooling fan damaged Replace fan
3. Oil level low or
contaminated
Fill or change filter
4. Excessive loading Reduce vehicle load
5. Air trapped in system
Operates Hot
Run vehicle slowly forward and then
reverse several times
6. Mowing conditions Heavy grass or embankments
1. Engine speed low Adjust setting
2. Oil level low or
contaminated
Fill or change filter
3. Bypass turned Turn to closed (horizontal) position
4. Excessive loading Reduce vehicle load
5. Air trapped in system Purge per instructions
6. Suspect internal Disassemble and inspect
7. Pulley or belt loose
No/Low Power
Tighten to specifications
1. Excessive speed input Adjust input speed above 1800 rpm
and below 3600 rpm
2. Oil level low or
contaminated
Fill or change filter
3. Excessive loading Reduce vehicle load
4. Air trapped in system Run vehicle slowly forward and then
reverse several times
5. Bypass valve open
Noisy Unit
Turn to closed (horizontal) position
7
Parker Hannifin Corporation
Hydraulic Pump/Motor Division
Greeneville, Tennessee USA