Chevrolet Silverado / GMC Sierra. Service manual — part 2304

Go to Step 2

Test (Gas
Engine
w/Engine Driven
Fan)

2

After continued operation of the A/C system, do
the low and the high side pressures equalize or
become static?

Go to Step 5

Go to Step 3

3

Refer to the pressures recorded during the A/C
System Performance Test.
Inspect for the following conditions:

The low side pressure is equal to or
greater than the specified pressure range of
the A/C Performance Table. Refer to Air
Conditioning (A/C) System
Performance Test (Diesel Engine) or
Air Conditioning (A/C) System
Performance Test (Gas Engine w/
Electric Cooling Fan) or Air
Conditioning (A/C) System
Performance Test (Gas Engine
w/Engine Driven Fan).

The high side pressure is less than the
specified pressure range of the A/C
Performance Table. Refer to Air
Conditioning (A/C) System
Performance Test (Diesel Engine) or
Air Conditioning (A/C) System
Performance Test (Gas Engine w/
Electric Cooling Fan) or Air
Conditioning (A/C) System
Performance Test (Gas Engine
w/Engine Driven Fan).

The low side refrigerant line at the
compressor feels cool-to-warm.

CAUTION:

Refer to Moving Parts and Hot Surfaces
Caution .

2008 Chevrolet Silverado 1500

2008 HVAC Heating, Ventilation, and Air Conditioning - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado

The high side refrigerant line at the
compressor feels warm-to-hot.

Do the listed conditions exist?

Go to Step 5

Go to Step 4

4

Refer to the pressures recorded during the A/C
System Performance Test.
Inspect for the following conditions:

The low side pressure is greater than the
specified pressure range of the A/C
Performance Table. Refer to Air
Conditioning (A/C) System
Performance Test (Diesel Engine) or
Air Conditioning (A/C) System
Performance Test (Gas Engine w/
Electric Cooling Fan) or Air
Conditioning (A/C) System
Performance Test (Gas Engine
w/Engine Driven Fan).

The high side pressure is less than the
specified pressure range of the A/C
Performance Table. Refer to Air
Conditioning (A/C) System
Performance Test (Diesel Engine) or
Air Conditioning (A/C) System
Performance Test (Gas Engine w/
Electric Cooling Fan) or Air
Conditioning (A/C) System
Performance Test (Gas Engine
w/Engine Driven Fan).

The low side refrigerant line at the
compressor feels warm.

The high side refrigerant line at the
compressor feels warm-to-hot.

CAUTION:

Refer to Moving Parts and Hot Surfaces
Caution .

Go to Air
Conditioning
(A/C) System
Performance
Test (Diesel
Engine) or Air
Conditioning
(A/C) System
Performance
Test (Gas
Engine w/
Electric Cooling
Fan) or Air
Conditioning
(A/C) System
Performance
Test (Gas

2008 Chevrolet Silverado 1500

2008 HVAC Heating, Ventilation, and Air Conditioning - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado

Do the listed conditions exist ?

Go to Step 5

Engine
w/Engine Driven
Fan)

5

The A/C system has a low refrigerant charge.
Evacuate and recharge the A/C system. Refer to
Refrigerant Recovery and Recharging.
Is the procedure complete?

Go to Step 6

-

6

1. Record the low and the high side pressures

as well as the instrument panel (I/P) air
outlet temperature after you perform the
repairs.

2. Compare the pressures and the panel outlet

temperature to those listed in the A/C
Performance Chart. Refer to Air
Conditioning (A/C) System
Performance Test (Diesel Engine) or
Air Conditioning (A/C) System
Performance Test (Gas Engine w/
Electric Cooling Fan) or Air
Conditioning (A/C) System
Performance Test (Gas Engine
w/Engine Driven Fan).

Are the readings within the specified ranges
found on the A/C Performance Chart?

Go to Step 13

Go to Step 7

7

The A/C compressor is malfunctioning.
Remove the expansion device and inspect for
contamination. Refer to Expansion (Orifice)
Tube Replacement.
Did you find metal flakes on the expansion
device?

Go to Step 9

Go to Step 8

8

Inspect the expansion device for a brown,
powdery residue indicating desiccant in the A/C
system.
Is a brown, powdery residue present?

Go to Step 11

Go to Step 12

1. Remove the suction and the discharge lines

from the compressor. Refer to Suction
Hose Replacement (LY2, LMF, L76

2008 Chevrolet Silverado 1500

2008 HVAC Heating, Ventilation, and Air Conditioning - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado

9

and L92) or Suction Hose Replacement
(LMM) and Discharge Hose
Replacement (LY2, LMF, L76 and
L92) or Discharge Hose Replacement
(LMM).

2. Inspect for metal flake contamination at

the line connections and the compressor
ports.

Is metal flake contamination present?

Go to Step 10

Go to Step 12

10

1. Replace the A/C compressor. Refer to Air

Conditioning Compressor
Replacement (LY2, LY5, LH6, L76,
L92 and LMG) or Air Conditioning
Compressor Replacement
(LLY/LMM) or Air Conditioning
Compressor Replacement (LU3).

2. Replace the orifice tube. Refer to

Expansion (Orifice) Tube
Replacement.

3. Evacuate and recharge the A/C system.

Refer to Refrigerant Recovery and
Recharging.

Is the repair complete?

Go to Step 13

-

11

1. Flush the A/C system. Refer to Flushing.

2. Replace the orifice tube. Refer to

Expansion (Orifice) Tube
Replacement.

3. Replace the A/C compressor. Refer to Air

Conditioning Compressor
Replacement (LY2, LY5, LH6, L76,
L92 and LMG) or Air Conditioning
Compressor Replacement
(LLY/LMM) or Air Conditioning
Compressor Replacement (LU3).

4. Replace the accumulator. Refer to Air

2008 Chevrolet Silverado 1500

2008 HVAC Heating, Ventilation, and Air Conditioning - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado