III-95
3. If the low side gauge shows a drop again, the valve is
not stuck. Clean the surfaces of the evaporator outlet
and the capillary coil or bulb. Make sure the coil or bulb
is securely fastened to the evaporator outlet and covered
with insulation material. Operate the system and check
performance.
Repair Procedure:
If the test did not result in proper operation of the expansion
valve, the valve is defective and must be replaced. Recover
all refrigerant from the system and replace the expansion
valve and the receiver-drier. Evacuate and recharge the
system with refrigerant, then check AC operation and per-
formance.
System High Pressure Side Restriction
Tip: Air from vents in the cab is only slightly cool. Look for
sweat or frost on high side hoses and tubing, and frost ap-
pearing right after the point of restriction. The hose or line
may be cool to the touch near the restriction.
Cause: There could be a kink in a line, or other restriction in the
high side of the system.
Troubleshooting & Service Procedures
Figure 8-11
Gauge reading, system high
pressure side restriction.
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