WD Catalog 2018

6-6

Chapter 6

- Service Tools & Their Use

SCHRADER TYPE VALVE

VALVE

MANIFOLD GAUGE SET

HOSE CONNECTOR

PIN IN CONNECTOR FORCES VALVE OPEN

AC SYSTEM PORT

BACK SEAT TYPE SERVICE VALVES

SERVICE PORT TO

GAUGE SET

VALVE IN MID-SEATED POSITION

FOR SYSTEM SERVICE

TURN CLOCKWISE TO CLOSE (FRONTSEAT)

TO ISOLATE THE COMPRESSOR

TURN COUNTER CLOCKWISE TO OPEN

(BACKSEAT) FOR AC SYSTEM OPERATION

5. System Service Valves (R-134a only)

New and unique service hose fittings have been specified for R-134a

systems. Their purpose is to avoid cross-mixing of refrigerants and lubri-

cants with R-12-based systems. The service ports on the system are quick

disconnect type with no external threads. They do contain a Schrader type

valve as shown in figure 6-5. The low side fitting has a smaller diameter

than the high-side attachment.

QUICK CONNECT HOSE END FITTING

WITH INTEGRAL SHUTOFF VALVE

SERVICE HOSE CONNECTION

DEPRESSOR PIN

SYSTEM SERVICE PORT

VALVE ASSEMBLED TO SERVICE PORT WITH VALVE IN THE OPEN POSITION

Figure 6-4

The valve drawings are

cutaway. The Schrader

valve in the upper portion of

the illustration (like a tire

air valve) is either closed or

open. The three illustrations

below show and describe

stem type valve positions.

Figure 6-5

This illustration shows

R-134a service ports and

hose end fittings.