AIR CONDITIONING SYSTEM REFRIGERANT (R-134A) MAINTENANCE - CONTINUED
PURGING - CONTINUED
Adjust nitrogen bottle regulator (5) to 200 psi (1379 kPa). Open nitrogen bottle control valve (1) and purging control
valve (2). Then, slowly open supply line valve (3). Check drain line (4) for gas flow.
Let nitrogen flow at 200 psi (1379 kPa) and let it flow for 1 to 2 minutes. If part or line was very wet, allow it to flow
until there is no trace of refrigerant oil or solid bits of dirt or grit flowing from drain tube.
Close nitrogen bottle control valve (1) and purging control valve (2) first, then close supply line valve (3).
Disconnect supply line valve (3) and drain line (4). Tightly cap both ends of part or line.
Recover refrigerant system.
Disconnect both ends of part or line being flushed. Tightly cap lines to rest of system.
Heat R-134a refrigerant in a dial-a-charge or pressurize refrigerant as recommended by manufacturer.
Connect dial-a-charge outlet hose to outlet side of system (this will ensure that R-134a will flow in reverse direction of
Connect a line from inlet side of system to a recovery/recycling station.
If system is extremely contaminated, install a receiver-drier inline as a pre-filter for recovery/recycling sta-
Turn on recovery/recycling station and open outlet valve for dial-a-charge. Allow about 2 pounds (1 kilogram) of R-
134a to flow through system.
Close supply line valve and wait for recovery station to shut off.
Disconnect supply line and drain line from dial-a-charge and recovery station. Connect lines to nitrogen bottle.
Purge system and check collection bottle for contaminants. Repeat process if needed.
Disconnect lines from part and tightly cap both ends of part.
Before charging, system must be recovered and evacuated with recovery and recycling station connected to
service and discharge port connections.
Obtain enough refrigerant to fully charge system. Set tank on a scale and weigh for correct amount of refrigerant to enter
system. This prevents overcharging, which could cause damage to compressor.
Charge refrigerant system:
If equipped with a recovery, recycling, and recharging system, charge system on high side following manu-
facturers instructions. If charging from a bulk container, perform following steps:
Turn tank (bulk container) upside down. With engine off, open high side hand valve. DO NOT open low side hand
Allow refrigerant to enter system until correct charge (by weight) has entered. Close high side hand valve.
Start engine and run it at 1500 rpm. Set cab air conditioner controls at maximum cooling and fan speed; refrigerant
compressor must engage.