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6-2
T--317
Only a R-134a manifold gauge set with self-sealing
hoses, as shown in Figure 6-3 (CTD P/N 07-00294-00,
which includes items 1 through 6) can be used when
working on the models covered within this manual.
Opened
(Backseated
Hand Valve )
Closed
(Frontseated
Hand Valve)
Low Pressure
Gauge
High Pressure
Gauge
A
B
C
A. Service Port to Low Side of System
B. Service Port to High Side of System
C. Service Port to Either: Refrigerant Cylinder, Oil
Container or Vacuum Pump
Figure 6-2. Manifold Gauge Set
1
2
3
4
5
6
To Low Side
To High Side
2
2
2
3
3
4
Red Hose
Yellow Hose
Blue Hose
Red
Knob
Blue Knob
1. Manifold Gauge Set
2. Hose Fitting (0.500-16 Acme)
3. Refrigeration or Evacuation Hoses
(SAE J2196/R-134a)
4 Hose Fitting w/O-ring (M14 x 1.5)
5. High Side Field Service Coupling
6. Low Side Field Service Coupling
Figure 6-3. Manifold Gauge Set Connection
6.4 REFRIGERANT RECOVERY
1. Disconnect the tube clamp connected to the baffle
plate on the liquid line process tube. Remove the
baffle plates covering both process tubes.
2. Install the piercing valve (refer to section 6.2) on the
liquid line process tube and the suction line process
tubes. The valve should be installed as close as
possible to the pinched-off end of the liquid line and
suction line process tubes. Make sure the tubing is a
full round diameter.
3. Install the 3/8 to 1/4 inch adapter to the1/4 inch flare
fitting on the piercing valves. Connect the high side
and low side of the R-134a manifold gauge set to the
3/8 inch hose fittings.
4. Connect the refrigerant recovery unit to the center
hose on the manifold gauge set. Close the piercing
valves, rotating the valve stems fully clockwise.
Following the instructions for your refrigerant
recovery unit start up and open the piercing valves
at the appropriate time by turning the valve stems
counter-clock wise.
5. When the refrigerant is fully recovered from the
system, remove the refrigerant recovery unit. Using
dry nitrogen break the vacuum and bring the system
pressure to a slightly positive pressure of 2 to 5 psig.
6. Remove any positive pressure from the system
through the manifold gauge set and leave the
piercing valve open and the gauge set center hose
open to prevent any pressure build-up in the
refrigeration system.
WARNING
Before proceeding with the repair make
certain that the stepper motor suction
modulation valve (SMV) is open (refer to
section 6.18) and that there is no positive
pressure in the system.
7. To reduce the time required for evacuation,
dehydration and refrigerant charging of the system,
perform the following steps.
S
Remove the piercing valves from the liquid
line and suction line process tubes.
S
Using the tubing cutter, cut the process tubes
below the pierced hole in liquid line and
suction line process tubes.
S
Place the 3/8 inch flare nuts on both process
tubes and flare the tube.
S
Connect the 3/8 inch to 1/4 inch flare adapter
and the 1/4 inch swivel elbow x R-134a
refrigerant adapter to the R-134a gauge set.