RAM 4500 Chassis Cab Truck 2WD L6-6.7L DSL Turbo (2008)
Expansion Block/Orifice Tube: Testing and Inspection
A/C ORIFICE TUBE
WARNING: The A/C liquid line between the A/C condenser and the A/C orifice tube can become hot enough to burn the skin. Use extreme
caution when performing the following test to prevent possible personal injury.
NOTE: The A/C orifice tube can be checked for proper operation using the following procedure. However, the A/C orifice tube is only serviced
as a part of the A/C liquid line. If the results of this test indicate that the A/C orifice tube is obstructed or missing, the A/C liquid line must be
replaced.
1. Confirm that the refrigerant system is properly charged See: Testing and Inspection/Component Tests and General Diagnostics/A/C Performance
Test .
2. Start the engine. Turn on the A/C system and confirm that the compressor clutch is engaged.
3. Allow the A/C system to operate for five minutes.
4. Lightly and cautiously touch the A/C liquid line near the condenser outlet at the front of the engine compartment. The A/C liquid line should be
hot to the touch.
5. Touch the A/C liquid line near the evaporator inlet at the rear of the engine compartment. The A/C liquid line should be cold to the touch.
6. If there is a distinct temperature differential between the two ends of the A/C liquid line, the A/C orifice tube is in good condition. If there is little
or no detectable temperature differential between the two ends of the A/C liquid line, the A/C orifice tube is obstructed or missing and the A/C
liquid line must be replaced See: Hose/Line HVAC/Service and Repair/A/C Line - Removal .