ADDING REFRIGERANT.

TM 5-4120-364-13

4-8.

ADDING REFRIGERANT.

General. Bubbles or a milky or frothy appearance of the refrigerant passing the sight

glass in normal operation is indication that the system needs additional refrigerant. The normal

refrigerant charge in the unit when shipped is 13 pounds 8 ounces of refrigerant R-12. Test for leaks

with available leak detector, repair leak and add refrigerant.

Adding Refrigerant. When adding refrigerant to the system, connect the service gage

hookup shown in figure 4-2 and proceed as follows:

(1) Turn stem of suction service valve counterclockwise as far as possible.

(2) Connect a line from the R-12 charging cylinder to connection on compressor

suction valve. Leave connection loose at the compressor valve and open charging cylinder outlet valve

long enough to purge all air from the charging line through the loose connection. Tighten charging line

connection at compressor suction valve when gas can be heard escaping from the loose connection.

(3) Turn suction service valve clockwise 3 or 4 turns.

(4) Open charging cylinder outlet valve 1 or 2 turns.

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