AC Hose - Low Side

This procedure covers removal and replacement of the low-side AC hose on a 2008 Dodge Viper with 8.4L V10 engine, including refrigerant recovery and system recharge.

Warnings

Tools required

Parts

• AC low-side hose assembly × 1 — Use OEM specification
• AC line O-rings × 4 — Use OEM specification
• PAG oil for AC system × 1 — Use OEM specification

Fluids

• ac_refrigerant

Preparation

1. Park vehicle on level surface and engage parking brake
2. Allow engine to cool completely if recently driven
3. Verify AC system has not been recently serviced (refrigerant pressure should be normal operating pressure)
4. Position refrigerant recovery machine and connect to service ports

Procedure

1. 1

   Recover refrigerant from AC system
   Connect refrigerant recovery machine to both high and low-side service ports. Follow recovery machine manufacturer instructions to completely evacuate all R-134a refrigerant from the system. Record the amount recovered for reference during recharge. Wait 5 minutes after recovery completes to ensure system is fully depressurized.
2. 2

   Access low-side AC hose
   Open hood and secure in raised position. The low-side (suction) AC hose runs from the evaporator outlet near the firewall to the compressor suction port on the engine. Confirm the actual routing and connection points against the vehicle-specific service manual, as this TXV-equipped system uses a receiver/drier rather than an accumulator. Identify the routing and connection points. The hose will have connections at the accumulator and at the compressor suction port.
3. 3

   Disconnect low-side hose at accumulator
   Locate the fitting where the low-side hose connects at the evaporator outlet (near the firewall). Determine whether the connection is a threaded fitting, block/plate fitting, or spring-lock coupling per the vehicle-specific service manual before disconnecting. Use a line wrench to hold the accumulator fitting stationary while using a second line wrench to loosen the hose connection nut. Remove the connection completely and cap or plug the accumulator port immediately to prevent moisture entry. Remove and discard the O-ring seals from the connection.
4. 4

   Disconnect low-side hose at compressor
   Locate the threaded fitting where the low-side hose connects to the compressor suction port (larger port on compressor, driver side of engine). Use a line wrench to hold the compressor fitting stationary while using a second line wrench to loosen the hose connection nut. Remove the connection completely and cap or plug the compressor port immediately to prevent moisture entry. Remove and discard the O-ring seals from the connection.
5. 5

   Remove mounting brackets and hose
   The low-side hose is secured to the vehicle with mounting brackets along its routing. Locate and remove fasteners securing these brackets to allow hose removal. Remove the complete low-side hose assembly from the vehicle. Note the exact routing path and any wire loom or other component clearances for installation reference.
6. 6

   Prepare new low-side hose
   Unpack new AC low-side hose assembly and verify it matches the original configuration. Lubricate new O-rings with small amount of clean PAG oil. Install new O-rings onto both connection ends of the new hose, ensuring they are seated properly in their grooves. Do not reuse old O-rings.
7. 7

   Install new low-side hose
   Route the new low-side hose along the same path as the original, ensuring it does not contact exhaust components, sharp edges, or moving parts. Install any mounting brackets and secure with their fasteners, but do not fully tighten until both hose connections are made.
8. 8

   Connect hose to compressor
   Remove the cap or plug from the compressor suction port. Lubricate the O-rings on the hose fitting with clean PAG oil. Connect the hose to the compressor suction port per the vehicle-specific method (threaded fitting or block/plate fitting with retaining bolt) and tighten to the manufacturer-specified torque value from the service manual. Do not over-torque the aluminum fitting.
9. 9

   Connect hose to accumulator
   Remove the cap or plug from the evaporator outlet connection. Lubricate the O-rings on the hose fitting with clean PAG oil. Connect the hose to the evaporator outlet fitting per the vehicle-specific method (threaded, block fitting, or spring-lock coupling) and secure it. If a threaded fitting, hold the mating fitting with one wrench while tightening the hose connection with the other. Tighten to the manufacturer-specified torque; do not over-torque the aluminum fitting.
10. 10

    Secure mounting brackets
    Verify the hose routing provides adequate clearance from all moving and hot components. Fully tighten all mounting bracket fasteners to secure the hose in position. Ensure no tension or strain exists at either connection point.
11. 11

    Evacuate AC system
    Connect vacuum pump to AC system through manifold gauge set. Evacuate the system to at least 29 inches of mercury vacuum for a minimum of 30 minutes. Monitor for vacuum loss which would indicate a leak. If vacuum holds steady for 10 minutes after pump stops, system is ready for recharge.
12. 12

    Recharge AC system
    Using proper refrigerant charging equipment, recharge the AC system with R-134a refrigerant. The system capacity and proper PAG oil quantity should be verified from the underhood AC specification label. Charge to the specified amount (typically measured by weight, not pressure). If significant oil was lost during hose removal, add the appropriate amount of PAG oil during recharge process.

Reassembly

1. Verify all AC line connections are tight and properly secured
2. Ensure hose routing provides clearance from hot exhaust components and moving parts
3. Check that all mounting brackets are fastened securely

Verification

• Start engine and activate AC system to maximum cooling
• Verify compressor engages and runs smoothly
• Use AC leak detector or soap solution to check all connections for leaks
• Monitor gauge pressures: low side should be 25-45 PSI at idle with AC on (ambient temperature dependent)
• Verify cold air output from cabin vents reaches appropriate temperature
• Allow system to run for 10 minutes and recheck all connections for leaks or oil seepage

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