3. TROUBLESHOOTING Possible cause
Action
PTO shaft does not rotate
If it does not rotate, the input shaft is damaged.
Repair the input shaft.
* Forward/reverse driving is not available
Insufficient transmission fluid
If the fluid is insufficient, the charge oil is not supplied sufficiently.
Replenish oil.
* Insufficient power when Dirty or discolored forward/reverse driving transmission fluid
The viscosity is too high or too low due to the aged or dirty fluid.
Change the fluid
* Delayed response
There are bubbles in fluid.
Repair the inlet line of gear pump.
Abnormal condition of HST pedal link
The link is damaged, loose or displaced.
Repair the related parts.
Low charge pressure (standard: 4 ~ 6 kg/cm2
The charge oil is insufficient due to the clogged oil filter.
Replace the filter.
(57 ~ 85 psi))
The charge relief valve is damaged.
Replace the charge relief valve.
The hydraulic line related to the 2nd gear pump is defective.
Repair the related parts. Refer to the "Hydraulic system" in this manual.
Too low pressure in high pressure relief valve for forward/reverse driving (standard: 300 kg/cm2
The relief valve is defective. (Especially, only one of two valves is defective.)
Replace the relief valve.
The HST plate is excessively worn.
Replace the plate.
The HST cylinder block and the piston are excessively worn.
Replace the HST.
ENGINE
GENERAL
* Forward/reverse driving is not available
* Max. speed is not achievable
(4,266 psi))
Cannot keep neutral position (The tractor moves slightly when in neutral)
Improperly adjusted HST pedal link, defective link
It is in neutral when the link is disconnected and the wheels are off from the ground.
Adjust and repair the link.
Power loss due to overheated oil
Check the oil cooler
The air passage of the cooler is blocked.
Clean it.
Check the oil
Improper, aged or dirty oil
Change the oil.
Check the HST valves
The valve springs and spool are stuck.
Clean the valves, replace the springs and replace the whole vales.
Check the leaking area
Check the oil seal, gasket and pipe O-ring.
Repair or replace as necessary.
Excessively raised charge pressure
Check if the HST filter is clogged.
Replace the filter.
Oil leakage
Replace the charge relief valve.
A/C AND INDEX HEATER
HYDRAULIC ELECTRIC & DIAGNOSIS SYSTEM
HYDRAULIC STEERING SYSTEM
STEERING SYSTEM FRONT AXLE
FRONT BRAKE AXLE
REAR BRAKE AXLE
REAR HSTAXLE
CLUTCH
* Noise in HST operation
6-14 170 of 450
DR72-W00
Dealer Copy -- Not for Resale
Symptom
TRANSMI SSION TRANSMISSION
Problem
TRANSMI SSION HST
SAFETY FIRST
HST - TROUBLESHOOTING
