Making A Complete Charge; Charging From Small Containers - Ford COUGAR 1968 Shop Manual

PART 16-2
-
Air Conditioning
16-29
CUT-AWAY VIEW
OF SERVICE VALVE
FIG.
14-Charging the Air Conditioning System
pump until the low pressure gauge
reads at least 25 inches, and as close
to 30 inches of vacuum as possible.
Continue vacuum pump operation
for 20 to 30 minutes to boil any
moisture out of the system. Close the
pump valve. Turn off the pump.
MAKING A COMPLETE
CHARGE
Check for leaks first (See Diag-
nosis and Ttsting in this part), re-
lease the pressure, then evacuate the
system. Leave both service valves a t
the mid-position (Fig. 14) and the vac-
uum pump valve closed. Leave the
low pressure manifold gauge valve a t
the maximum counterclockwise or
open position. Set the high pressure
manifold gauge valve a t the maximum
During the charging, the high pres-
sure may build up to an excessive
value. This can be caused by an over-
charge of refrigerant, or an over-
heated engine, in combination with
high surrounding temperatures. Nev-
er allow the high pressure to exceed
240 pounds while charging. Stop the
engine, determine the cause, and cor-
rect it.
After the proper charge has been
made, close the Refrigerant-I2 tank
valve, and check the system pressures
for proper operation. Set both serv-
ice valves a t the maximum counter-
clockwise position. Remove the gauge
set, and cap the service valve gauge
ports and valve stems.
CHARGING FROM SMALL
CONTAINERS
valve, and open the valve. Keep the
can in an upright position. When the
can is empty (no frost showing),
close the valve, remove the empty
can, attach a new one, and open the
valve again.
Allow only the specified amount of
refrigerant to be pumped into the
system (Part 16-5). The frost line on
the can will indicate what portion
of the can has entered the system.
Then close the valve at the can. The
system will then have been charged
with the correct weight in pounds of
refrigerant. Falcon, Fairlane, and
Montego models take exactly two
15 oz. cans. Mustang and Cougar
models take less than two cans
(Part 16-5).
Check the system pressures, set
both service valves at the maximum
- -
clockwise or closed position. Set all counterclockwise position. Remove
controls to the maximum cold posi-
Refrigerant-12 is available in 15 OZ.
the gauge set, and cap the service
tion. cans. A scale is not necessary if valve gauge ports and valve stems.
Open the Refrigerant-12 tank valve.
these small containers are used in-
Run the engine a t 1500 rpm. Charge
stead of a tank.
the system until the weight of refriger-
Attach the hose that would nor-
ant is to specification.
mally g o to the large tank to the
It may be 'necessary to place the
special valve that is provided for the
Refrigerant-I2 tank in a container of
small cans. Close the valve (maxi-
hot water at about 150 degrees F. to
mum clockwise position) and follow
force the gas from the tank during
the procedure for leak testing, evac-
uating and charging the system as
charging.
eve;
heat the Refrigerant-I2 tank
previously given.
with a torch. A dangerous explosion
For charging, attach a 15 oz.
FIG.
15-Com~ress0r
Oil
Level
may result.
can of Refrigerant-12 to the special
Check