WD Catalog 2018

Chapter 9

- Refrigerants

9-8

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Run the vacuum pump for at least an hour to remove the

moisture from the system.

The moisture must turn to gas before the pump can pull it out. The

moisture takes time to boil away, so that it can be drawn out of the system.

Your vacuum pump can draw most of the air out pretty quickly. But a

deep vacuum requires more time; the deeper the vacuum the longer it

takes to get there. To ensure the least possible amount of air and moisture

in the system, buy a good quality vacuum pump, take care of it, and use it

for at least an hour

WARNING

Lubricants removed during the recovery process must

be replaced with new lubricants.

Charging the AC system

*Use a charging station whenever possible.

When adding a full charge of refrigerant, you can put it in as a gas or as

a liquid. Adding refrigerant as a liquid is faster but can damage the

compressor if not done correctly. The procedure you use, and where you

add the refrigerant in the AC system makes a difference. When using

refrigerant as a liquid, never add more than two thirds of system require-

ments as a liquid. Finish charging the system using gas. Always keep the

refrigerant containers in an upright position so that no liquid is drawn

into the system.

Refer to the

Charging with Refrigerant Gas

section below for the

procedure for gas charging. Refer to the

Charging the System with Liquid

Refrigerant

section for the procedure for liquid charging.

Charging with Refrigerant Gas (on the Low Side)

Perform this procedure to charge with refrigerant gas:

Use a charging meter or station to select the exact amount of

refrigerant required. Never add more than the amount of

refrigerant recommended by the manufacturer (in pounds

and ounces). To measure, use a container and scale, or charg-

ing station.

Figure 9-4

Vacuum pump.