Textron JACOBSEN R-311 69166, Technical/Repair Manual

Page: 189 / 402

5-26 4203781 First Edition
HYDROSTATIC POWER TRAIN
5
Troubleshooting
Mower Will Not Move Forward or Reverse
Mower Will Not Reach Full Speed
Mower Moves When Traction Pedal Is in Neutral
Probable Cause Remedy
Hydraulic oil not at correct level in reservoir. Fill reservoir to correct level. (Refer to “Safety, Operation, and
Maintenance Manual” for the correct oil specifications.)
Tow valve open. Close tow valve. (Refer to “Safety, Operation, and Maintenance
Manual.”)
Low charge pressure. Test charge pressure relief valve setting. (See “Charge Pressure
Test” on page 5-34.) Repair or replace charge pressure relief
valve as needed. (See “Control Valve” on page 5-54.)
Gear pump damaged. Test and repair. (See “Charge Pressure Test” on page 5-34.)
Front axle motor worn or damaged. Test motor. (See “Front Axle Motor Test” on page 5-42.) Repair or
replace motor as needed. (See “Front Axle Motor” on
page 5-58.)
Traction pump worn or damaged. Test pump. (See “Traction Pump Tests” on page 5-40.) Repair or
replace pump as needed. (See “Traction Pump” on page 5-49.)
Damaged traction linkage. Repair traction linkage. (See “Traction Pedal” on page 9-9 and
“Traction Linkage” on page 5-68.)
Front axle assembly worn or damaged. Repair front axle. (See “Front (Drive) Axle Assembly” on
page 5-61.)
Probable Cause Remedy
Hydraulic oil not at correct level in reservoir. Fill reservoir to correct level. (Refer to “Safety, Operation, and
Maintenance Manual” for the correct oil specifications.)
Tow valve open. Close tow valve. (Refer to “Safety, Operation, and Maintenance
Manual.”)
Air in hydraulic system (air bubbles in hydraulic oil). Check suction line for air leaks. Repair as needed. Operate
various hydraulic systems until hydraulic system is free of air.
Traction linkage not properly adjusted. Adjust traction linkage. (See “Traction Linkage Adjustments” on
page 5-29.)
Low charge pressure. Test charge pressure relief valve setting. (See “Charge Pressure
Test” on page 5-34.) Repair or replace charge pressure relief
valve as needed. (See “Control Valve” on page 5-54.)
Gear pump worn or damaged. Test gear pump. (See “Charge Pressure Test” on page 5-34.)
Repair or replace gear pump as needed. (See “Gear Pump” on
page 6-58.)
Taction pump worn or damaged. Test pump. (See “Traction Pump Tests” on page 5-40.) Repair or
replace pump as needed. (See “Traction Pump” on page 5-49.)
Front axle motor worn or damaged. Test motor. (See “Front Axle Motor Test” on page 5-42.) Repair or
replace motor as needed. (See “Front Axle Motor” on
page 5-58.)
Engine RPM low Verify and adjust engine RPM. (See engine manufacturer’s
manual for further instructions.)
Probable Cause Remedy
Traction linkage not properly adjusted. Adjust traction linkage. (See “Traction Linkage Adjustments” on
page 5-29.)