MAINTENANCE UPON DEMAND MAINTENANCE UPON DEMAND CHECKING THE AIR-CONDITIONING SYSTEM Check the air-conditioning system twice a year, in spring and au- tumn. CHECKING THE COOLANT LEVEL If the liquid gets into your eyes or on your hands, it may cause loss of sight or frostbite: Therefore never loosen any part of the refrigerant circuit. 65_15 Operate the cooler of the air-conditioning system for 5 - 10 min- utes, then touch the high pressure portion and low pressure por- tion of the compressor (or high pressure hose and low pressure hose joint) with your hand. At the same time, inspect the flow of coolant (R134a) through the sight glass to check the gas level.
Sight glass Contact your Komatsu dealer for this inspection. The sight glass is installed next to the receiver at the side of the condenser. The steps on the right have to be unscrewed and the condenser swung out for access. Receiver GK100335 7-30 COLOR CONDITION NORMAL ABNORMAL Temperature of high and low pressures pipes High pressure pipe is hot. Low presure pipe is cold. Clear difference in tempera- ture. High pressure pipe is warm. Low pressure pipe is cold. Little difference in tempera- ture. Amost no difference in tem perature between high an low pressure pipes. Sight glass Almost transparent. All bub- bles disappear if the engine speed is increased or reduced.
Bubbles are always visible. Sometimes becomes trans- parent, or white bubbles appear. Opaque substance is visib in the fluid. Pipe connections Properly connected. Some parts contaminated with oil. Some parts heavily staine with oil. General conditions of cooler Coolant level correct, no abnormalitities. Ready for use. Ther may be a leak some- where. Call service repair shop for inspection. Almost all coolant has leaked out. Contact servic repair shop immediately.