Service Manual

627333-A 5-49
HVAC Testing and Adjusting
1. Find refrigerant capacity for system.
2. Install high and low pressure hoses and purge
hoses, refer to Testing and Adjusting, Manifold
Gauge Set (Refrigerant) - Install.
3. Hand tighten charging hose from manifold gauge
set directly to valve on refrigerant tank. Open valve
on top of refrigerant tank to allow the flow of
refrigerant through charging hose to manifold
gauge set.
4. Loosen hose at manifold gauge set for two to three
seconds and tighten connection, this will purge air
from line.
5. Place refrigerant tank on scale so valve is at
bottom. Check weight of tank.
NOTE: A heater blanket may be required when
charging an air conditioning system with a
partially full refrigerant tank.
6. Open high pressure valve on manifold gauge set.
This action allows liquid refrigerant to charge
system through the high pressure side of
compressor.
7. Check weight of refrigerant tank often as weight will
decrease as refrigerant enters the system. When
required amount of refrigerant (system capacity)
has entered system, close valve and high pressure
valve. Closing valves stops flow of refrigerant. For
example, 1.8 kg (4 lb) of refrigerant has entered a
system with 1.8 kg (4 lb) capacity.
8. For correct system operation, disconnect charging
hose and conduct a performance check.