Table 9-2.--A/M26U-4 Troubleshooting Chart
Trouble
Probable Cause
Remedy
Motor and pump do not operate.
Motor selector valve is not properly
Properly position valve.
positioned.
Leak in the gas system.
Tighten all fittings.
Defective seals in between compressed
Replace seals.
gas and driving gas sections.
Pump will not cycle or cycling is slow. Gas supply is inadequate.
Check to ensure gas supply to inlet is
adequate.
Vent or outlet line is blocked.
Check for blocked vent or outlet line.
Leaking at flow and/or pilot tubes.
Replace O-rings on flow and pilot tubes.
Some units may require two O-rigns at
the ends of the tubes.
Pilot valve(s) are malfuctioning.
Repair pilot valve(s).
Buildup of residue in the muffler.
Clean or replace muffler.
Defective piston.
Replace motor and pump.
Motor and pump will not operate at low Excess friction of spool packings of the Repair, making certain that spool
gas drive pressures.
control valve.
O-rings are lubricated.
Defective pump O-rings. (If gas supply Replace O-rings in following order:
Pump will not build up pressure.
a. Spool O-rings
continuous.)
b. Piston O-rings
c. Sleeve O-rings, if leaking persists
Pump cycles erratically.
Pilot valve is leaking.
Repair pilot valves with Kit 27420.
Excessive moisture outside of muffler.
Filter is full of water.
Drain filter.
Excessive leaking out of vent.
Rod seals are worn.
Replace gas section seals.
Lever control valve leaks.
Faulty diaphragm.
Replace.
Tire and tube leaking.
Valve is leaking.
Replace valve core.
Tube is punctured.
Repair or replaces.
Service hose leaking.
Hose coupling muts are loose.
Tighten coupling nuts.
Hose is split.
Replace hose.
Purifier leaking.
Purifier head is loose.
Tighten purifier head.
Defective O-rings.
Replace O-rings.
Pressure regulator leaking.
Regulator piston is leaking.
Repair regulator.
Hose and tube asswemblies leaking.
Coupling nuts are loose.
Tighten coupling nuts.
Pressure regulator does not deliver
Pressure in cylinders is too low.
Recharge cylinders.
charging pressure.
Regulator is defective.
Repair/replace regulator.
9-18
