AC Hose - High Side

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

Warnings

Tools required

Parts

• AC high-side hose assembly × 1 — Use OEM specification
• AC line O-ring kit × 1 — 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 operated
3. Verify AC system operation and note any existing leaks or abnormal sounds
4. Place drip pan or absorbent material under work area to catch residual refrigerant oil

Procedure

1. 1

   Recover refrigerant from AC system
   Connect the AC recovery machine to the service ports following the machine manufacturer's instructions. Recover all R-134a refrigerant from the system according to EPA regulations. Record the amount of refrigerant recovered for recharging reference. Once recovery is complete and gauges show zero pressure, wait 5 minutes and verify no pressure builds back up, confirming complete recovery.
2. 2

   Access high-side hose at compressor
   The high-side hose connects to the AC compressor discharge port on the passenger side of the engine bay. Clean the connection area thoroughly with a lint-free cloth to prevent contamination. Locate the tube nut or flare fitting connecting the high-side hose to the compressor discharge fitting.
3. 3

   Disconnect hose from compressor
   Using the appropriate line wrench or flare nut wrench, hold the compressor discharge port stationary while loosening the tube nut connecting the high-side hose. Expect to turn the nut counterclockwise. Once loosened, unscrew completely by hand and separate the hose from the compressor. A small amount of residual oil may drip out. Immediately cap or plug both the compressor discharge port and the hose end to prevent contamination.
4. 4

   Access high-side hose at condenser
   The condenser is mounted at the front of the vehicle. Trace the high-side hose from the compressor forward to the condenser inlet connection, typically located on the passenger side of the condenser. Clean the connection area thoroughly.
5. 5

   Disconnect hose from condenser
   Using a line wrench, hold the condenser inlet fitting stationary while loosening the tube nut securing the high-side hose. Turn counterclockwise to loosen. Once loose, unscrew by hand and separate the hose from the condenser. Cap or plug both the condenser inlet and hose end immediately to prevent contamination and moisture entry.
6. 6

   Remove high-side hose from vehicle
   Note the routing path of the hose, including any mounting brackets or clips securing it to the chassis or engine bay components. Remove any fasteners or release clips securing the hose along its routing path. Carefully extract the high-side hose from the engine bay, taking care not to damage other components or hoses during removal.
7. 7

   Inspect and prepare new hose
   Inspect the fittings on both ends of the new high-side hose to ensure they are clean and undamaged. Check that new O-rings are installed at both connection points. If O-rings are not pre-installed, install new O-rings from the kit, coating them lightly with refrigerant oil (PAG oil specific to the system) to aid sealing and prevent damage during installation. Do not use petroleum-based lubricants.
8. 8

   Route new hose in vehicle
   Route the new high-side hose through the engine bay following the same path as the original. Ensure the hose does not contact sharp edges, hot exhaust components, or moving parts like belts or pulleys. Maintain adequate clearance from the engine block and manifolds. Secure any mounting brackets or clips along the routing path, but leave connection fittings loose for now.
9. 9

   Connect hose to condenser
   Remove the cap or plug from the condenser inlet fitting. Align the new high-side hose fitting with the condenser inlet and thread the tube nut on by hand, turning clockwise. Hand-tighten until snug, ensuring the fitting threads smoothly without cross-threading. Using a line wrench and holding the condenser fitting stationary, tighten the tube nut to the proper torque specification. Do not over-tighten as this can damage the flare seat or O-ring.
10. 10

    Connect hose to compressor
    Remove the cap or plug from the compressor discharge port. Align the new high-side hose fitting with the compressor discharge port and thread the tube nut on by hand, turning clockwise. Hand-tighten until snug. Using a line wrench while holding the compressor fitting stationary, tighten the tube nut to the proper torque specification. Verify the hose routing does not place strain on either connection.
11. 11

    Vacuum test the AC system
    Connect a vacuum pump to the AC system service ports. Evacuate the system to at least 29 inches of mercury (inHg) vacuum and maintain for a minimum of 30 minutes. After 30 minutes, close the valves and shut off the vacuum pump. Monitor the vacuum gauge for 10 minutes. Vacuum should hold steady with no more than 1 inHg loss, indicating no leaks. If vacuum drops significantly, locate and repair the leak before proceeding.
12. 12

    Recharge AC system
    With the system still under vacuum, connect the refrigerant supply following the recharge machine instructions. Add the appropriate amount of R-134a refrigerant (refer to the underhood AC specification label for the exact capacity for this vehicle). Add the manufacturer-specified amount of PAG oil if significant oil was lost during hose replacement (typically 1-2 oz for a single hose replacement). Start the engine and activate the AC system to full cold with maximum blower speed. Complete the recharge process and verify proper system pressures on both high and low sides using manifold gauges.
13. 13

    Leak test and verify operation
    With the AC system running, carefully inspect all connections for signs of leaks (oil residue, hissing sounds). If UV dye was added during recharge, use a UV light to inspect for leaks at both hose connections. Verify the AC compressor engages properly, condenser fans activate, and cold air is produced at the vents. Monitor system pressures to ensure they are within normal operating range (typically 200-250 psi high side, 25-35 psi low side at idle with ambient temperature around 75-80°F).

Reassembly

1. Ensure all hose mounting brackets and clips are properly secured along the routing path
2. Verify hose has adequate clearance from all moving parts, hot surfaces, and sharp edges
3. Double-check both connection fittings are properly torqued and show no signs of leakage

Verification

• Start the engine and set AC to maximum cold with high blower speed
• Verify cold air is produced at all vents within 1-2 minutes
• Check that AC compressor engages and disengages properly with AC button cycling
• Confirm no unusual noises from compressor or hissing sounds at connections
• Verify system pressures are within normal operating range using manifold gauges
• Inspect all connections for any signs of refrigerant or oil leakage
• Test AC performance under various conditions (idle, highway speed, hot ambient temperature)

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