Operating instructions

TM 11574A-OI

3-10

(e) Refrigerant leak checking.

WARNING

Never use air for leak testing. It has been determined that pressurized, air-rich mixtures

of refrigerants and air can undergo combustion when exposed to an ignition source.

The recommended procedure for finding leaks in a system is with an R-134a

electronic leak detector. Testing joints with soapsuds is satisfactory only for locating

large leaks.

If the system is without refrigerant, charge the system with refrigerant 134a to build

up pressure between 30 to 50 psig @ (2.1 to 3.5 kg/cm). Remove refrigerant

cylinder and leak-check all connections.

NOTE

Only refrigerant 134a should be used to pressurize the system. Any other gas or vapor

will contaminate the system, which will require additional purging and evacuation of the

system.

If required, remove refrigerant using a refrigerant recovery system and repair any

leaks.

Evacuate and dehydrate the unit (refer to Evacuation and dehydration paragraph 3-

10b(3)).

Charge unit per Refrigeration charge paragraph 3-10b(4) .