Dodge Ram Truck 1500-2500-3500. Manual — part 2081

10. Install the bolt (7) that secures the A/C suction and discharge line assembly to the A/C compressor. Tighten the

bolt to 28 N·m (20 ft. lbs.).

11. Connect the wire harness connector (5) to the A/C pressure transducer.

12. Remove the tape or plugs from the opened suc-

tion line fitting and the accumulator outlet tube.

13. Lubricate new rubber O-ring seals with clean

refrigerant oil and install them onto the accumula-
tor tube fitting. Use only the specified O-rings as
they are made of a special material for the
R-134a system. Use only refrigerant oil of the
type recommended for the A/C compressor in the
vehicle.

14. Connect the A/C suction line (6) to the spring-lock

coupler (1) on the accumulator (5) and install the
secondary retaining clip (7) (Refer to 24 - HEAT-
ING

& AIR

CONDITIONING/PLUMBING/COU-

PLER-REFRIGERANT LINE - INSTALLATION).

15. Install the air filter housing cover (Refer to 9 -

ENGINE/AIR INTAKE SYSTEM).

16. Reconnect the negative battery cable.

17. Evacuate the refrigerant system (Refer to 24 -

HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYSTEM EVACUATE).

18. Charge the refrigerant system (Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING - STANDARD PRO-

CEDURE - REFRIGERANT SYSTEM CHARGE).

8.3L ENGINE

1. Remove the tape or plugs from the opened suction

line fitting and the accumulator outlet tube.

2. Lubricate new rubber O-ring seals with clean refrig-

erant oil and install them onto the accumulator tube
fitting. Use only the specified O-rings as they are
made of a special material for the R-134a system.
Use only refrigerant oil of the type recommended
for the A/C compressor in the vehicle.

3. Connect the A/C suction line (6) to the spring-lock

coupler (1) on the accumulator (5) and install the
secondary retaining clip (7) (Refer to 24 - HEAT-
ING

&

AIR

CONDITIONING/PLUMBING/COU-

PLER-REFRIGERANT LINE - INSTALLATION).

24 - 324

PLUMBING

DR/DH

4. Install the A/C suction line (5) into the two refriger-

ant line retainer clips (2) located at the top of the
fan shroud (1).

5. Install the air filter housing cover (Refer to 9 -

ENGINE/AIR

INTAKE

SYSTEM/AIR

FILTER

HOUSING - INSTALLATION).

6. Position the A/C suction line (1) into the engine

compartment.

7. Remove the tape or plugs from the opened fitting

on the A/C suction line and the inlet port on the
A/C compressor (2).

8. Lubricate a new seal with clean refrigerant oil and

install it onto the suction line fitting. Use only the
specified seal as it is made of a special material for
the R-134a system. Use only refrigerant oil of the
type recommended for the A/C compressor in the
vehicle.

9. Install the A/C suction line onto the A/C compres-

sor.

10. Install the bolt (5) that secures the A/C discharge

line to the A/C compressor. Tighten the bolt to 20
N·m (15 ft. lbs.).

11. Reconnect the negative battery cable.

12. Evacuate the refrigerant system (Refer to 24 -

HEATING & AIR CONDITIONING/PLUMBING - STANDARD PROCEDURE - REFRIGERANT SYSTEM EVAC-
UATE).

13. Charge the refrigerant system (Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING - STANDARD PRO-

CEDURE - REFRIGERANT SYSTEM CHARGE).

OIL-A/C REFRIGERANT

DESCRIPTION

The refrigerant oil used in R-134a refrigerant systems is a synthetic-based, polyalkylene glycol (PAG), wax-free
lubricant. Mineral-based R-12 refrigerant oils are not compatible with PAG oils, and should never be introduced to
an R-134a refrigerant system.

There are different PAG oils available, and each contains a different additive package. Use only refrigerant oil of the
same type as recommended to service the refrigerant system (always refer to the specification tag included with
the replacement A/C compressor or the underhood A/C system specification tag).

DR/DH

PLUMBING

24 - 325

The Saden SD-7 A/C compressor used in this vehicle is designed to use ND-15 PAG refrigerant oil. Use only this
type of refrigerant oil when servicing the A/C compressor for the 5.9L Diesel engine.

The Denso 10S17 A/C compressor used in this vehicle is designed to use ND-8 PAG refrigerant oil. Use only this
type of refrigerant oil when servicing the A/C compressor for the 3.7L, 4.7L, 5.7L and 8.3L engines.

OPERATION

After performing any refrigerant recovery or recycling operation, always replenish the refrigerant system with the
same amount of the recommended refrigerant oil as was removed. Too little refrigerant oil can cause A/C compres-
sor damage, and too much can reduce A/C system performance.

PAG refrigerant oil is more hygroscopic than mineral oil, and will absorb any moisture it comes into contact with,
even moisture in the air. The PAG oil container should always be kept tightly capped until it is ready to be used.
After use, recap the oil container immediately to prevent moisture contamination.

STANDARD PROCEDURE

REFRIGERANT OIL LEVEL

When an A/C system is assembled at the factory, all components except the A/C compressor are refrigerant oil free.
After the refrigerant system has been charged and operated, the refrigerant oil in the A/C compressor is dispersed
throughout the refrigerant system. The accumulator, A/C evaporator, A/C condenser and the A/C compressor will
each retain a significant amount of the needed refrigerant oil.

It is important to have the correct amount of refrigerant oil in the A/C system. This ensures proper lubrication of the
A/C compressor. Too little oil will result in damage to the A/C compressor, while too much oil will reduce the cooling
capacity of the A/C system and consequently result in higher discharge air temperatures.

CAUTION: The refrigerant oil in the R-134a A/C system is unique depending on the A/C compressor used.
Use only PAG oils that are designed to work with R-134a refrigerant and the A/C compressor in the vehicle.
Always refer to the underhood A/C System Specification Label for the correct oil designation. The oil con-
tainer should be kept tightly capped until it is ready for use and then tightly capped after use to prevent
contamination from dirt and moisture. Refrigerant oil will quickly absorb any moisture it comes in contact
with, therefore, special effort must be used to keep all R-134a system components moisture-free. Moisture
in the refrigerant oil is very difficult to remove and will cause a reliability problem with the A/C compressor.

NOTE: Most reclaim/recycling equipment will measure the lubricant being removed during recovery. This
amount of lubricant should be added back into the system. Refer to the reclaim/recycling equipment man-
ufacturers instructions.

It will not be necessary to check the oil level in the A/C compressor or to add oil, unless there has been an oil loss.
An oil loss may occur due to a rupture or leak from a refrigerant line, a connector fitting, a component, or a com-
ponent seal. If a leak occurs, add 30 milliliters (1 fluid ounce) of refrigerant oil to the refrigerant system after the
repair has been made. Refrigerant oil loss will be evident at the leak point by the presence of a wet, shiny surface
around the leak.

Refrigerant oil must be added when an accumulator, A/C evaporator or A/C condenser is replaced. See the Refrig-
erant Oil Capacities chart. When an A/C compressor is replaced, the refrigerant oil must be drained from the old
compressor and measured. Drain all of the refrigerant oil from the new A/C compressor, then fill the new compres-
sor with the same amount of refrigerant oil that was drained out of the old compressor.

24 - 326

PLUMBING

DR/DH

REFRIGERANT OIL CAPACITIES

Component Name

ml.

oz.

Total A/C System Fill

180

6

A/C Accumulator

60

2

A/C Condenser

30

1

A/C Evaporator

60

2

A/C Compressor

Drain and measure the oil from the old
compressor - see text.

REFRIGERANT-A/C

DESCRIPTION

The refrigerant used in this air conditioning system is a HydroFluoroCarbon (HFC), type R-134a. Unlike R-12, which
is a ChloroFluoroCarbon (CFC), R-134a refrigerant does not contain ozone-depleting chlorine. R-134a refrigerant is
a non-toxic, non-flammable, clear, and colorless liquefied gas.

Even though R-134a does not contain chlorine, it must be reclaimed and recycled just like CFC-type refrigerants.
This is because R-134a is a greenhouse gas and can contribute to global warming.

OPERATION

R-134a refrigerant is not compatible with R-12 refrigerant in an A/C system. Even a small amount of R-12 refrigerant
added to an R-134a refrigerant system will cause A/C compressor failure, refrigerant oil sludge or poor A/C system
performance. In addition, the polyalkylene glycol (PAG) synthetic refrigerant oils used in an R-134a refrigerant sys-
tem are not compatible with the mineral-based refrigerant oils used in an R-12 refrigerant system.

R-134a refrigerant system service ports, service tool couplers and refrigerant dispensing bottles have all been
designed with unique fittings to ensure that an R-134a refrigerant system is not accidentally contaminated with the
wrong refrigerant (R-12). There are also labels posted in the engine compartment of the vehicle and on the A/C
compressor to identify that the A/C system is equipped with R-134a refrigerant.

TUBE-A/C ORIFICE

DESCRIPTION

The fixed A/C orifice tube is installed in the rear sec-
tion of the A/C liquid line and provides a restriction in
the liquid refrigerant line between the A/C condenser
and the A/C evaporator. This restriction established
the pressure differential between the high and low-
pressure sides of the A/C system. The A/C orifice tube
includes a diffuser screen (1), O-ring seals (2) to seal
it to the inner wall of the A/C liquid line, an inlet filter
screen (3) and the fixed orifice (4).

OPERATION

The fixed A/C orifice tube is used to meter the flow of liquid refrigerant into the A/C evaporator. The high-pressure
liquid refrigerant from the A/C condenser expands into a low-pressure liquid as it passes through the metering orifice
and diffuser screen of the A/C orifice tube.

The A/C orifice tube is not serviceable. The A/C orifice tube cannot be repaired and, if faulty or plugged, it must be
replaced as part of the A/C liquid line.

DR/DH

PLUMBING

24 - 327