General Fault Detection - JUNTTAN PM 20L Operator's Manual

JUNTTAN
Routine service section

7.17 GENERAL FAULT DETECTION

THE ENGINE STALLS AT LOW RPM
If the engine consistently stalls at low rpm when load is applied, the setting of the pump
angle may have wandered. Contact Junttan. Check the fuel filters.
THE SWING WORKS ERRATICALLY
If the swing function works erratically check that there is no dirt in the valve which
controls the direction of slewing.
THE TRACKS DO NOT STAY UNDER TENSION
If the track chain does not stay under tension, there is a leak in the tensioning system.
The leak can be in the grease nipple, in the seals of the piston, or in the seals of the
cylinder body.
HYDRAULIC OIL HEATS UP MORE THAN NORMAL
If the hydraulic oil heats up more than normal with no change in pressure settings and
no other apparent reason, check the oil coolers.
Check that the fans are working and that the air can circulate. Check that the coolers are
clean.
SEVERAL OR ALL HYDRAULIC FUNCTIONS ARE ERRATIC
If several or all hydraulic functions are erratic there is dirt or water in the oil. Take a
sample and test it. Drain the water from the hydraulic tank. If there is water in the
hydraulic oil make sure that the manhole is properly closed.
THE HYDRAULIC OIL FILLING PUMP MALFUNCTIONS
If you cannot fill hydraulic oil with the hand pump check that there is no oil leak in on
the suction side. If the pump is heavy check that the valve is open to the hydraulic tank
and check that the filter used is not blocked (You can by-pass the filter for testing).
THE FUEL FILLING PUMP DOES NOT PUMP FUEL
If the fuel filling pump does not fill the fuel check that the pump is rotating, the sieve is
not blocked and there is no leak on the suction side.
THE TRACK DRIVE MOTORS DO NOT ROTATE
Check by the pressure gauges in the cab that the pressure builds up when the lever for
the track motor is moved. Check for both directions. Next connect a pressure gauge to
the brake circuit and check that the brake cylinder gets the proper pressure to open. Dirt
can jam the over centre valve of the brake cylinder. If everything checks OK this far,
disconnect the motor from the transmission to see if it works when it stands alone.
THE LEADER TELESCOPE DOES NOT HOLD THE LEADER UP
If the leader telescope does not hold the leader up the probable cause is dirt in the
valves, the piston seal of the cylinder leaks or the bleed screw leaks.
n DANGER
Do not open valves or bleed screw when the telescope is up position.
141