Service Manual

TX 413 Service Manual 11-5
HYDRAULIC TROUBLESHOOTING
Rev. 001
Pumps
Pump Troubleshooting
Hydraulic pumps transfer uids by suction, pressure,
or both. Pumps convert mechanical energy into
hydraulic pressure and ow.
Inspect the plumbing for bent, kinked/attened lines,
leaks and dirt build up.
Inspect the pump housing for discolored surfaces.
Ensure the linkage is assembled correctly and it is
not bent or binding.
Look for evidence of recently installed parts and
inquire with the owner/operator.
Pump not delivering oil
• Reservoir uid level low
• Inlet line to the pump plugged
• Air drawn in through the inlet side of pump
• Insufcient pump speed
• Dirt/debris in the pump
• Worn or broken internal pump parts
• Pump belt or connection
No Pressure (Pump doesn't produce pressure. Relief
valve relief regulates maximum pressure.)
• Oil recirculating back to the reservoir instead of
downstream
• Broken hydrostatic pump piston, valve broken or
stuck in the open position
• Relief valve damaged, stuck, adjusted/misadjusted,
no ow
• Leak
Slow/Erratic Behavior
• Oil temperature too cold
• Incorrect oil viscosity
• Restriction or air leak at the pump inlet
• Insufcient pump speed
• Internal pump parts sticking
• Internal pump parts out of tolerance due to wear
• Contaminated oil
• Belt slippage (hydrostatic pump)
Noisy Pump
• Inlet line restricted or plugged
• Air drawn in through the inlet side of pump
• Reservoir level low
• Fluid viscosity (thick or thin)
• Pump speed too high
• Contaminated oil
• Broken or worn pump parts
• Belt or pulley (hydrostatic pump)
Excessive Wear
• Abrasives in the oil
• Oil viscosity too low or too high
• Continued high pressure operation (Above pump
specication)
• Cavitation due to air leaks or restrictions
• Misaligned pump drive shaft
Excessive Oil Leakage
• Drive shaft seals damaged
Broken Internal Parts
• Maximum pressure limits for pump exceeded
(hydrostatic pump)
• Lack of oil
• Abrasive contaminants in the oil