MCC EM-1 - Page 43

4-- 3© 2012 Mobile Climate Control T-299 Rev. 08/2012
a. Preparing M anifold Gauge/Hose Set For Use
1.. If the manifold gauge/hose set is new or was
exposed to the atmosphere it will need to be
evacuated to remove contaminants and air as
follows:
2.. Backseat (turn coun terclockwise )both field
service couplings (see Figure 4-1) and midseat
both hand valves.
3.. Connect the yellow hose to a reco very m achine,
vacuum pum p or refrigerant 134a cylinder.
Depending on tools available and service to be
performed.
4.. Evacuate to 10 inches of vacuum and then charge
with R-134a to a slightly positive pressure of 0.1
kg/cm@ (1.0 psig).
5.. Front seat both manifold gauge set valves and
disconnect from cylinder. The gauge set is now
ready for use.
b.Connecting Manifold Gauge/Hose Set
To connect the manifold gauge set, (See Figure 4-2)
do the following.
1.. Connect the high side field service coupling (see
Figure 4-1) to the discharge line service valve
port.
2.. Turn the high side field service coupling knob
(red) clockwise, which will open the high side of
the system to the gauge set.
3.. Connect the low side field service coupling to the
suction service valve port.
4.. Turn the low side field service coupling knob
(blue) clockwise, which will open the low side of
the system to the gauge set.
WARNING
To prevent trapping liquid refrigerant in
the manifold gauge set be sure set is
brought to suction pressure before
disconnecting.
c. Removing the Manifold Gauge Set
1. Backseat (turn cou n terclockwise) the high side
(discharge) field service coupling (red knob).
2.. Midseat both hand valves on the manifold gauge
set and allow the pressure in the manifold gauge
set to be drawn down to suction pressure. This
returns any liquid that may be in the high side hose
to the system.
3.. Backseat the low side ( suction) field service
coupling (red knob) and frontseat (clockwise)
both manifold gauge set valves. Remove the
couplings from th e service po rts.
4.. Install both service port caps (finger-tight only).