Dodge RAM TRUCK 1500 1995 Service Manual page 1676

B R
HEATING AND AIR CONDITIONING 24 - 7
R E F R I G E R A N T
SERWIGB
INDEI
page
Charging Refrigerant System . . . . . . . . . . . . . . . . . . 7
Evacuating Refrigerant System
7
Leak Testing Refrigerant 7
LEAK TESTING REFRIGERANT
REVIEW WARNINGS AND CAUTIONS IN
THIS GROUP BEFORE LEAK TESTING.
If A/C system is not cooling properly, determine if
system is fully charged. Refer to Refrigerant System
Diagnosis Chart. If the system is empty evacuate the
A/C system and charge system with 0.272 kg (0.10
oz.) R-134a refrigerant. Refer to Charging Refriger­
ant System for instructions. To detect a leak in the
system, perform the following procedures.
(1) Position the vehicle in a wind free work area.
This will aid in detecting small leaks.
(2) Run the engine with the A/C off for 5 to 7 min­
utes.
(3) Open hood 5 minutes prior to leak test. This
will dissipate any accumulated refrigerant in the en­
gine compartment.
(4) With the engine not running, use an R-134a
Electronic Leak Detector and search for leaks. Move
probe slowly along the bottom side of lines and fit­
tings, because R-134a is heavier than air. Fittings,
lines, or components that appear to be oily usually
indicates a refrigerant leak.
(5) To inspect the evaporator core for leaks. Set the
blower at low speed and the selector in PANEL and
RECIRC mode check for leaks at CENTER panel out­
lets.
RECOWERING REFRIGERANT SYSTEi
REVIEW WARNINGS AND CAUTIONS IN
THIS GROUP BEFORE RECOVERING REFRIG­
ERANT SYSTEM.
R-134a refrigerant is a hydrofluorocarbon (HFC)
that does not contain chlorine. R-134a refrigerant Re­
covery/Recycling Station that meets SAE standard
J2210 must be used to recover the refrigerant. Refer
to the operating instructions provided with the equip­
ment for proper operation.
EVACUATING REFRIGERANT SYSTEi
REVIEW WARNINGS AND CAUTIONS IN
THIS GROUP BEFORE EVACUATING SYSTEM.
If the A/C system has been open to the atmosphere,
it must be evacuated before the system can be
charged. Moisture and air mixed with refrigerant will
raise the compressor head pressure above acceptable
page
Recovering Refrigerant System . . . . . . . . . . . . . . . . 7
Refrigerant Oil Level Check . . . . . . . . . . . . . . . . . . . 7
operating levels. This will reduce the performance of
the air conditioner and damage the compressor. Mois­
ture will boil at near room temperature when ex­
posed to vacuum. To evacuate the refrigerant system
use following procedure:
(1) Connect a suitable charging station and mani­
fold gauge set to the vehicle.
(2) Open the low and high side valves and start
vacuum pump. When suction gauge reads 88 kPa (26
in. Hg) vacuum or greater, close all valves and turn
off vacuum pump. If system fails to reach specified
vacuum, the system has a leak that must be cor­
rected. If system maintains the specified vacuum for
30 minutes, start the vacuum pump. Then open the
suction and discharge valves and evacuate an addi­
tional 10 minutes.
(3) Close all valves. Turn off and disconnect the
vacuum pump.
The system is now ready to be charged with refrig­
erant.
CHARGING REFRIGERANT SYSTEi
REVIEW WARNINGS AND CAUTIONS IN
THIS GROUP BEFORE CHARGING SYSTEM.
After the system has been tested for leaks and
evacuated, a refrigerant charge can be injected into
the system. Refer to refrigerant capacities for proper
amount of refrigerant charge. Charge the system us­
ing a Recovery/Recycling/Charging Station approved
for R-134a refrigerant. Refer to the instructions pro­
vided with the equipment for proper operation.
REFRIGERANT CHARGE CAPACITY
The R-134a system charge capacity is 0.9 kg (2
lbs.).
REFRIGERANT OIL LEWEL CHECK
When an A/C system is assembled at the factory,
all components (except the compressor) are refriger­
ant oil free. After the system has been charged and
operated, the oil in the compressor is dispersed
through the system. The accumulator, evaporator,
condenser and compressor will retain a significant
amount of oil.
It is important to have the correct amount of oil in
the A/C system. This will ensure proper lubrication of
the compressor. Too little oil will result in damage to