Dodge Ram Truck 1500-2500-3500. Manual — part 2069

ACCUMULATOR-A/C

DESCRIPTION

The A/C accumulator (5) is mounted in the engine
compartment between the evaporator outlet tube (2)
and the A/C suction line (6). An integral mounting
bracket (4) is used to secure the accumulator to the
dash panel (3). The A/C low side service port (1) is
mounted to the top of the A/C accumulator.

CAUTION: Use only O-ring seals specified for the
vehicle. Failure to use the correct O-ring seal will
cause the refrigerant system connections to leak.

The A/C accumulator has no serviceable parts except
for the rubber O-ring seals, low side service port
valve, cap and secondary retaining clips. The O-ring
seals used on the connections are made from a spe-
cial type of rubber not affected by R-134a refrigerant.
The O-ring seals must be replaced whenever the A/C
accumulator is removed and installed.

The A/C accumulator cannot be repaired and, if faulty
or damaged, it must be replaced.

OPERATION

Refrigerant enters the A/C accumulator (1) mostly as a
low pressure vapor through the inlet tube (2). Any liq-
uid, oil-laden refrigerant falls to the bottom of the can-
ister, which acts as a separator. A desiccant bag (3) is
mounted inside the accumulator canister to absorb
any moisture which may have entered and become
trapped within the refrigerant system A filter (4) is also
mounted inside the canister to trap any foreign mate-
rial that may have entered the refrigerant system dur-
ing assembly. The low pressure vapor exits the A/C
accumulator through the outlet tube (5). On this
model, the low side service port (6) is located at the
top of the accumulator.

The A/C accumulator cannot be repaired. If the A/C
accumulator is faulty or damaged, or if the refrigerant
system has been contaminated or left open to the
atmosphere for an indeterminable period or if the A/C
compressor has failed, it must be replaced.

REMOVAL

WARNING: Review the warnings and cautions in the front of this section before performing the following
operation (Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING - WARNINGS) and (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - CAUTIONS).

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1. Disconnect and isolate the negative battery cable.

2. Recover the refrigerant from the refrigerant system

(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING

-

STANDARD

PROCEDURE

-

REFRIGERANT RECOVERY).

3. Remove the air filter housing cover to gain access

to the A/C accumulator (9) (Refer to 9 - ENGINE/
AIR INTAKE SYSTEM).

4. Remove the secondary retaining clip (11) from the

spring-lock coupler (1) that secures the A/C suction
line (10) to the accumulator outlet tube (2).

5. Using the proper A/C line disconnect tool, discon-

nect the A/C suction line from the A/C accumulator
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING/COUPLER-REFRIGERANT

LINE

-

REMOVAL).

6. Loosen the bolts (8) that secure the A/C accumu-

lator to the bracket located on the dash panel (7).

7. Remove the secondary retaining clip (4) from the spring-lock coupler (6) that secures the accumulator inlet tube

(3) to the evaporator outlet tube (5).

8. Using the proper A/C line disconnect tool, disconnect the accumulator inlet tube from the evaporator outlet tube

(Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING/COUPLER-REFRIGERANT LINE - REMOVAL).

9. Remove the O-ring seals from the accumulator tube fittings and discard the seals.

10. Install plugs in, or tape over the opened refrigerant system connections.

11. Remove the A/C accumulator from the engine compartment.

INSTALLATION

NOTE: If the A/C accumulator is being replaced, add 60 milliliters (2 fluid ounces) of refrigerant oil to the
refrigerant system. Use only refrigerant oil of the type recommended for the A/C compressor in the vehicle.

1. Position the A/C accumulator (9) onto the bracket

located on the dash panel (7) in the engine com-
partment. Do not tighten the accumulator bracket
bolts (8) at this time.

2. Remove the tape or plugs from the opened refrig-

erant system connections.

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

erant oil and install them onto the accumulator tube
fittings (1 and 6). 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 recom-
mended for the A/C compressor in the vehicle.

4. Connect the spring-lock coupler that secures the

accumulator inlet tube (3) to the evaporator outlet
tube (5) and install the secondary retaining clip (4)
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING/COUPLER-REFRIGERANT

LINE

-

INSTALLATION).

5. Tighten the accumulator bracket bolts to 4.5 N·m (40 in. lbs.).

6. Connect the A/C suction line (10) to the accumulator outlet tube (2) and install the secondary retaining clip (11)

(Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING/COUPLER-REFRIGERANT LINE - INSTALLATION).

7. Install the air filter housing cover (Refer to 9 - ENGINE/AIR INTAKE SYSTEM).

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

CEDURE - REFRIGERANT SYSTEM EVACUATE).

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

CEDURE - REFRIGERANT SYSTEM CHARGE).

10. Reconnect the battery negative cable.

COMPRESSOR-A/C

DESCRIPTION

A/C COMPRESSOR

The A/C system on models equipped with the 5.9L
engine diesel use a Sanden SD-7 reciprocating swash
plate-type compressor (1). This A/C compressor has a
fixed displacement of 165 cubic centimeters (10.068
cubic inches) and has both the suction and discharge
ports (2) located on the cylinder head (3) at the rear of
the compressor.

The A/C system on models equipped with the 3.7L,
4.7L, 5.7L AND 8.3L engines use a Denso 10S17
reciprocating swash plate-type compressor (1). This
A/C compressor has a fixed displacement of 170 cubic
centimeters (10.374) and has both the suction and
discharge ports (2) located on the cylinder head (3) at
the rear of the compressor.

A label identifying the use of R-134a refrigerant is located on both A/C compressors.

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HIGH PRESSURE RELIEF VALVE

A high pressure relief valve is located on the compressor cylinder head, which is at the rear of the A/C compressor.
This mechanical valve is designed to vent refrigerant from the A/C system to protect against damage to the A/C
compressor and other A/C system components, caused by condenser air flow restriction or an overcharge of
refrigerant.

OPERATION

A/C COMPRESSOR

The A/C compressor is driven by the engine through an electric clutch, drive pulley and belt arrangement. The A/C
compressor is lubricated by refrigerant oil that is circulated throughout the refrigerant system with the refrigerant.

The A/C compressor draws in low-pressure refrigerant vapor from the A/C evaporator through its suction port. It then
compresses the refrigerant into a high-pressure, high-temperature refrigerant vapor, which is then pumped to the
A/C condenser through the compressor discharge port.

The A/C compressor cannot be repaired and, if faulty or damaged, it must be replaced. The compressor clutch,
pulley and bearing assembly, and clutch field coil are available for service.

HIGH PRESSURE RELIEF VALVE

The high pressure relief valve vents refrigerant from the A/C system when a discharge pressure of 3445 to 4135
kPa (500 to 600 psi) or above is reached. The high pressure relief valve closes with a minimum discharge pressure
of 2756 kPa (400 psi) is reached.

The high pressure relief valve vents only enough refrigerant to reduce the A/C system pressure, and then re-seats
itself. The majority of the refrigerant is conserved in the A/C system. If the high pressure relief valve vents refrig-
erant, it does not mean the valve is faulty.

The high pressure relief valve is factory-calibrated and cannot be adjusted or repaired, and must not be removed or
otherwise disturbed. The valve is only serviced as a part of the A/C compressor.

DIAGNOSIS AND TESTING

A/C COMPRESSOR

When investigating an A/C system related noise, you must first know the conditions under which the noise occurs.
These conditions include: weather, vehicle speed, transmission in gear or neutral, engine speed, engine tempera-
ture, and any other special conditions. Noises that develop during A/C operation can often be misleading. For exam-
ple: What sounds like a failed front engine bearing or connecting rod, may be caused by loose bolts, nuts, mounting
brackets or a loose compressor clutch assembly.

Drive belts are speed sensitive. At different engine speeds and depending upon drive belt tension, drive belts can
develop noises that are mistaken for an A/C compressor noise. Improper drive belt tension can cause a misleading
noise when the compressor clutch is engaged, which may not occur when the compressor clutch is disengaged.
Check the accessory drive belt condition and tension as described in Cooling before beginning this procedure.

1. Select a quiet area for testing. Duplicate the complaint conditions as much as possible. Turn the A/C compressor

On and Off several times to clearly identify the compressor noise. Listen to the A/C compressor while the clutch
is engaged and disengaged. Probe the A/C compressor with an engine stethoscope or a long screwdriver with
the handle held to your ear to better localize the source of the noise.

2. Loosen all of the compressor mounting hardware and retighten. Check the compressor clutch retainer. Be certain

that the clutch field coil is mounted securely to the A/C compressor, and that the clutch plate and pulley are
properly aligned and have the correct air gap (Refer to 24 - HEATING & AIR CONDITIONING/CONTROLS/
CLUTCH-A/C COMPRESSOR - INSTALLATION).

3. To duplicate high-ambient temperature conditions (high head pressure), restrict the air flow through the A/C con-

denser. Install a manifold gauge set or a scan tool to be certain that the discharge pressure does not exceed
2760 kPa (400 psi).

4. Check the refrigerant system plumbing for incorrect routing, rubbing or interference, which can cause unusual

noises. Also check the refrigerant lines and hoses for kinks or sharp bends that will restrict refrigerant flow, which

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