Hummer H1 (2006+). Manual - part 329

11-50 Heating/Ventilation/Air Conditioning (HVAC)

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Installation

1.

Attach one hose end to the auxiliary unit heater core port and secure with the clamp (Figure  11-47).

2.

Route the hose through the grommet to the engine area.

3.

Connect the hose to the hose splice and secure with the clamp.

4.

Install the two P-clamps to the underbody securing the installed hose to the existing hoses.

5.

Fill the cooling system (Refer to section 4).

6.

Install the air cleaner induction tube (Refer to section 3).

7.

Pressure test the cooling system and check for leaks.

8.

Install the center console.

9.

Start the engine and run until the engine warms up.

10. Check the heating units for proper operation.

AUXILIARY A/C DRAIN TUBE(S) REPLACEMENT

Removal

1.

Remove the center console.

2.

Remove the clamps from the drain tube section being replaced (Figure  11-49).

3.

Remove the drain tube.

Figure 11-49:   Auxiliary A/C Drain Tube Replacement

Installation

1.

Install the drain tube section and secure with the clamps (Figure  11-49).

2.

Install the center console.

REFRIGERANT SOLENOID REPLACEMENT

Removal

1.

Discharge the air conditioning system.

2.

Remove the center console.

3.

Using two wrenches for equalized support, remove the auxiliary high pressure hose from the refrigerant solenoid. Remove and
discard the O-ring.

4.

Using two wrenches for equalized support, remove the refrigerant solenoid from the high pressure line to the auxiliary
expansion valve. Remove and discard the O-ring.

Installation

1.

Using two wrenches for equalized support, install the refrigerant solenoid to the high pressure line from the auxiliary expan-
sion valve, tighten to 11-13 lb-ft. (15-18 N•m).

DRAIN

TEE

DRAIN TUBE

TUBE

CLAMPS

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 Heating/Ventilation/Air Conditioning (HVAC)  11-51

2.

Install the auxiliary high pressure hose to the refrigerant solenoid. Using two wrenches for equalized support, tighten to 11-13
lb-ft. (15-18 N•m).

3.

Install the center console.

4.

Evacuate, charge and leak test the system.

5.

Start the engine and check the A/C system operation.

AUXILIARY HIGH-PRESSURE HOSE REPLACEMENT

NOTE: Production hoses have a full underbody length of foil backed heat resistant sleeving. Replacement hoses should have the
same level of thermal protection. 

Removal

1.

Discharge the air conditioning system.

2.

Remove the air cleaner assembly and the air induction tube (Section 3).

3.

Remove the center console.

4.

Using two wrenches to equalize support, remove the auxiliary high pressure hose from the expansion valve manifold. Remove
and discard the O-ring (Figure  11-50).

5.

Using two wrenches for equalized support, remove the auxiliary high pressure hose from the auxiliary expansion valve.
Remove and discard O-ring (Figure  11-51).

6.

Remove the two P-clamps securing the hose to the underbody.

7.

From under the vehicle, pull the high-pressure hose through the grommet.

Figure 11-50:

.

Auxiliary High Pressure Hose Connection, Front

Figure 11-51:   Auxiliary High-Pressure Hose Connection, Rear

HIGH PRESSURE HOSE

CONNECTION (AUX.)

EXPANSION VALVE

MANIFOLD

HEATER TUBE

AUXILIARY

O-RING

LOW PRESSURE 

HIGH PRESSURE HOSE 

MOUNTING BRACKET

UNIT

EXPANSION

VALVE

A/C HOSE

11-52 Heating/Ventilation/Air Conditioning (HVAC)

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Installation

1.

Route the expansion valve end of the hose through the grommet to the auxiliary unit.

2.

Lubricate and position the O-ring on the high pressure hose and hand thread the hose fitting onto the expansion valve. Using
two wrenches for equalized support, tighten to 11-13 lb-ft. (15-18 N•m) (Figure  11-51).

3.

Route the other end of the hose to the expansion valve manifold (Figure  11-50).

4.

Lubricate and position the O-ring on the hose and secure to the high expansion valve manifold. Using two wrenches for
equalized support, tighten to 11-13 lb-ft. (15-18 N•m).

5.

Install the two P-clamps to secure the hoses to the underbody.

6.

Install the center console.

7.

Evacuate, charge and leak test the system.

8.

Start the engine and check the A/C operation.

AUXILIARY LOW-PRESSURE HOSE REPLACEMENT

Removal

1.

Discharge the air conditioning system.

2.

Remove the air cleaner assembly and the air induction tube (Refer to section 3).

3.

Using two wrenches for equalized support, remove auxiliary low-pressure hose from the low-pressure hose fitting. Remove
and discard the O-ring (Figure  11-50).

4.

Remove the two P-clamps securing the hoses to the underbody.

5.

Remove the center console.

6.

Remove the prestite tape from the low-pressure hose. Using two wrenches for equalized support, remove the hose from the
auxiliary unit. Remove and discard the O-ring (Figure  11-51).

7.

From under the vehicle, pull the low pressure hose through the grommet.

CAUTION: To avoid potential thread or fitting damage, hand start connections before using wrenches. 

Installation

1.

Route the evaporator end of the hose through the grommet to the auxiliary unit.

2.

Lubricate and position the O-ring on the hose and secure to the auxiliary unit. Using two wrenches for equalized support,
tighten to 21-27 lb-ft. (29-37 N•m) (Figure  11-51).

3.

Route the other end of the low-pressure hose under the hood to the low pressure fittings.

4.

Lubricate and position the O-ring and secure the auxiliary low pressure hose to the existing low pressure hose fitting. Using
two wrenches for equalized support, tighten to 24-28 lb-ft. (33-38 N•m) (Figure  11-50).

5.

Install the two P-clamps to secure the hoses to the underbody.

6.

Install the center console.

7.

Evacuate, charge and leak test the system.

8.

Start the engine and check the A/C operation.

AUXILIARY EVAPORATOR/HEATER CORE REPLACEMENT

Removal

1.

Remove the auxiliary unit from the vehicle.

2.

Remove the four screws and the plenum from the housing.

3.

With the auxiliary unit on a bench, remove the six plastic locking pins securing the unit housing halves together (Figure  1).

4.

Remove the four screws from the blower motor support.

5.

Remove the four screws securing the side brackets to the upper housing half.

6.

Separate the housing halves.

7.

Remove the blower motor assembly from the bottom housing.

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 Heating/Ventilation/Air Conditioning (HVAC)  11-53

8.

Remove the evaporator/heater core assembly from the lower housing.

9.

Remove the plastic stick pins and the mesh filter from the evaporator/heater core assembly.

NOTE: If the expansion valve is to be reused, remove the valve from the evaporator/heater core assembly and install on the re-
placement unit.

Installation

1.

Install the mesh filter on the evaporator/heater core assembly with the plastic stick pins (Figure  11-52).

2.

Install the evaporator/heater core assembly in the lower housing.

3.

Install the blower motor assembly in the lower housing.

4.

Install the upper housing to the lower housing with the six plastic locking pins, the four blower motor support screws and the
four screws securing the side brackets to the upper housing.

5.

Install the plenum on the housing with the four screws.

6.

Install the auxiliary unit into the vehicle.

7.

Evacuate, charge and leak test the A/C and the heating system.

AUXILIARY BLOWER MOTOR REPLACEMENT

Removal

1.

Disconnect the auxiliary unit mounting hardware and tilt the unit up to gain access to the blower motor support screws.

2.

Remove the support screws and the screws securing the side brackets to the upper housing half.

3.

Separate the housing halves and remove the blower motor assembly from the lower housing.

 Installation

1.

Install the blower motor assembly in the lower housing and the housing halves back together.

2.

Install the side brackets to the upper housing half with the screws and the support screws.

3.

Position the auxiliary unit and secure with the mounting hardware.