Hydrostatic Drive System Troubleshooting Table 27: Hydrostatic Drive System Troubleshooting Problem
Possible Cause Parking brake is applied. Low hydraulic oil level.
Travel drive does Low or no charge pressure. not operate in either Hydrostatic pump(s) relief valve direction malfunction. Restraint bar not lowered. Seat or restraint bar switch malfunction. Rear hydrostatic pump relief Right side drive valve malfunction. doesn’t operate in either direction; left Rear hydrostatic pump control side operates rod linkage malfunction. normally Right side drive doesn’t operate in one direction
Rear hydrostatic pump relief valve malfunction. Rear hydrostatic pump malfunction. Front hydrostatic pump relief valve malfunction.
Left side drive doesn’t operate in either direction; right Linkage front hydrostatic pump side operates control rod linkage malfunction. normally Left side drive doesn’t operate in one direction
Front hydrostatic pump relief valve malfunction. Front hydrostatic pump malfunction. Hydraulic oil viscosity too heavy. Low hydraulic oil level.
Travel drive system noisy Air in hydraulic system. Drive motor(s) or hydrostatic pump(s) internal damage/ leakage. 171
Corrective Action Release parking brake. Top off hydraulic oil. See “Checking Hydraulic Oil Level” on page 147. See “Fluid Capacities/ Lubricants” on page 187 for proper oil grade. Contact dealer. Lower restraint bar. Check switch electrical connections; repair as necessary. Contact dealer. Check linkage connection at control levers and neutral centering mechanisms. Adjust/repair as necessary. Contact dealer. Contact dealer.
Contact dealer. Check linkage connection at control levers and neutral centering mechanisms. Adjust/repair as necessary. Contact dealer. Contact dealer. Replace existing oil with proper viscosity oil. See “Fluid Capacities/Lubricants” on page 187. Allow longer warm-up. Top off hydraulic oil. See “Checking Hydraulic Oil Level” on page 147. See “Fluid Capacities/ Lubricants” on page 187 for proper oil grade. Cycle lift and tilt cylinders to maximum stroke and maintain pressure for short time to clear air from system. Also check for low oil level in reservoir; top off as necessary. Contact dealer.
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