Dodge Nitro. Manual — part 760

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
refrigerant, 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.

COMPRESSOR-A/C

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 must be replaced if inoperative or damaged. The compressor
clutch, pulley and bearing assembly, and clutch field coil are available for service. If an internal failure of the
A/C compressor has occurred, the A/C receiver/drier must also be replaced. See REMOVAL.

DIAGNOSIS AND TESTING

COMPRESSOR-A/C

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
temperature, and any other special conditions. Noises that develop during A/C operation can often be
misleading. For example: 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

CAUTION: Be certain to adjust the refrigerant system oil level when replacing an A/C

compressor. See REFRIGERANT OIL LEVEL. Failure to properly adjust the
refrigerant oil level can prevent the A/C system from operating as
designed and can cause serious A/C compressor damage.

CAUTION: The A/C receiver/drier must be replaced if an internal failure of the A/C

compressor has occurred. Failure to replace the A/C receiver/drier can
cause serious damage to the replacement A/C compressor.

2007 Dodge Nitro R/T

2007 HVAC Heating & Air Conditioning - Service Information - Nitro

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.

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

A/C condenser. 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 can cause noises. See REFRIGERANT LINES.

5. If the noise is from opening and closing of the high pressure relief valve, recover, evacuate and recharge

the refrigerant system. See REFRIGERANT SYSTEM RECOVERY, and REFRIGERANT
SYSTEM EVACUATE .

6. If the high pressure relief valve still does not seat properly, replace the A/C compressor. See

REMOVAL.

REMOVAL

2.8L ENGINE

WARNING:

Refer to the applicable warnings and cautions for this system before
performing the following operation. See WARNING, and CAUTION. Failure
to follow the warnings and cautions could result in possible personal
injury or death.

NOTE:

The A/C compressor can be removed from the engine and repositioned without
disconnecting the refrigerant lines or discharging the refrigerant system.
Discharging is not necessary if servicing the A/C clutch or various engine
components.

NOTE:

LHD model shown in illustrations. RHD model similar.

2007 Dodge Nitro R/T

2007 HVAC Heating & Air Conditioning - Service Information - Nitro

Fig. 123: Refrigerant Line System
Courtesy of CHRYSLER LLC

1. Disconnect and isolate the negative battery cable.

2. Recover the refrigerant from the refrigerant system. See REFRIGERANT SYSTEM RECOVERY.

3. Remove the air cleaner housing. Refer to REMOVAL .

4. Remove the air inlet tube from the throttle body and the charge air cooler.

5. Remove the battery. Refer to REMOVAL .

6. Remove the radiator fan and fan shroud. Refer to REMOVAL .

7. Remove the accessory drive belt. Refer to REMOVAL .

8. Remove the generator. Refer to REMOVAL .

9. On LHD models, remove the two nuts (2) that secure the A/C suction line (4) to the top of the engine.

10. Remove the nuts (5) that secures the A/C suction line and A/C discharge line (1) to the A/C compressor

(3).

11. Disconnect the A/C suction and discharge lines from the A/C compressor and remove and discard the O-

ring seals and gaskets.

2007 Dodge Nitro R/T

2007 HVAC Heating & Air Conditioning - Service Information - Nitro

Fig. 124: A/C Clutch Field Coil Connector, Bolts & A/C Compressor
Courtesy of CHRYSLER LLC

12. Disconnect the engine wire harness from the A/C clutch field coil connector (1).

13. Support the A/C compressor (3) and remove the three bolts (2) that secure the compressor to the engine.

14. Remove the A/C compressor from the engine compartment.

15. Install plugs in, or tape over the opened refrigerant line fittings and the compressor ports.

4.0L ENGINE

WARNING:

Refer to the applicable warnings and cautions for this system before
performing the following operation. See WARNING, and CAUTION. Failure
to follow the warnings and cautions could result in possible serious or
fatal injury.

NOTE:

The A/C compressor can be removed from the engine and repositioned without
disconnecting the refrigerant lines or discharging the refrigerant system.
Discharging is not necessary if servicing the A/C clutch or various engine
components.

2007 Dodge Nitro R/T

2007 HVAC Heating & Air Conditioning - Service Information - Nitro