AC Hose - Low Side

Replace the low-side AC hose on a 2005 Dodge Viper 8.3L V10, requiring evacuation and recharge of the AC system, removal of underbody panels, and replacement of hose O-rings.

Warnings

Tools required

Parts

• Low-side AC hose assembly × 1 — Use OEM specification
• AC line O-rings × 4 — Use OEM specification for hose fitting size
• PAG oil (for AC system) × 1 — 46 viscosity PAG oil

Fluids

• R-134a

Preparation

1. Park vehicle on level surface and engage parking brake
2. Allow engine to cool completely if recently operated
3. Gather all required tools and replacement parts
4. Verify replacement low-side hose matches original in routing and fitting configuration

Procedure

1. 1

   Recover AC refrigerant
   Connect AC recovery machine to service ports. Start with engine off. Recover all R-134a refrigerant from the system following recovery machine manufacturer instructions. Allow recovery machine to complete cycle and verify system pressure reaches atmospheric. Record the amount of refrigerant and oil removed for recharge reference.
2. 2

   Raise and support vehicle
   Lift the front of the vehicle using a floor jack at the designated front jack point. Support on jack stands rated for vehicle weight. The low-side AC hose runs along the frame rail and requires underbody access. Ensure vehicle is stable before working underneath.
3. 3

   Remove belly pan fasteners
   Remove the front underbody panel fasteners to access the AC line routing. Remove approximately 8-10 fasteners securing the forward belly pan section. The low-side hose is routed along the passenger side frame rail from the accumulator/drier to the compressor. Lower the panel to gain access.
4. 4

   Locate low-side hose connections
   Identify the low-side (suction) AC hose. On the Viper's system it connects from the evaporator outlet to the low-side (suction) port on the compressor. Confirm the actual system architecture (receiver/drier vs accumulator, orifice tube vs expansion valve) against the vehicle before proceeding. The low-side hose is typically the larger diameter line and will have the low-side service port (larger cap) along its length. Trace the entire hose path and identify any mounting clips or brackets securing it to the frame or body.
5. 5

   Disconnect hose at accumulator/drier
   Determine the fitting type at the low-side hose connection (threaded flare, spring-lock quick-connect, or bolted block fitting). Use the appropriate tool — a line wrench for a threaded flare, or an AC line disconnect tool for a spring-lock coupler — and carefully separate the connection. This is typically a threaded flare-style fitting. Support the accumulator body with one hand while loosening the fitting to prevent twisting the canister. Once loose, separate the connection. Some residual oil may drip; have a shop towel ready. Inspect the O-ring condition and discard.
6. 6

   Disconnect hose at compressor
   Locate the low-side hose connection at the compressor suction port (typically on top or side of compressor). Using a line wrench, loosen the threaded fitting. The compressor is mounted low on the front of the engine. Once the fitting is loose, separate the hose from the compressor. Cap both the compressor port and hose end immediately to prevent moisture and debris entry. Inspect and discard the O-ring.
7. 7

   Release mounting brackets
   Release any mounting clips or brackets securing the low-side hose to the frame rail or body. These are typically push-type clips or P-clamps. Note the exact routing and clip positions for reinstallation. Remove the old low-side hose from the vehicle.
8. 8

   Prepare new hose assembly
   Unpack the new low-side AC hose assembly. Verify it matches the original in length, fitting types, and service port location. Install new O-rings on both fittings (accumulator end and compressor end). Lightly lubricate each O-ring with fresh PAG oil (approximately 2-3 drops per O-ring). Ensure O-rings are seated properly in their grooves and not twisted.
9. 9

   Route and install new hose
   Route the new low-side hose along the frame rail following the exact path of the original. Ensure the hose does not contact any sharp edges, hot components, or moving parts. Secure the hose in the original mounting clips or brackets, ensuring proper support along its length. The service port should be accessible from the top of the engine bay.
10. 10

    Connect hose to compressor
    Remove the protective cap from the compressor suction port. Thread the low-side hose fitting onto the compressor by hand to start, ensuring it threads smoothly without cross-threading. Hand-tighten fully, then use a torque wrench and line wrench to tighten to the OEM-specified AC line fitting torque (verify exact value from the 2005 Viper service manual before final tightening).
    Torque spec

    AC Line Fittings20 Nm (15 lb-ft)
11. 11

    Connect hose to accumulator/drier
    Remove the protective cap from the accumulator/drier port. Thread the low-side hose fitting onto the accumulator by hand, ensuring proper alignment. Hand-tighten fully, then use a torque wrench and line wrench to tighten to specification. Support the accumulator body to prevent twisting.
    Torque spec

    AC Line Fittings20 Nm (15 lb-ft)
12. 12

    Reinstall belly pan
    Raise the front underbody panel back into position. Reinstall all fasteners and verify the panel is properly secured. Ensure no AC lines are pinched or contacting the panel.
13. 13

    Lower vehicle
    Remove jack stands and carefully lower the vehicle to the ground. Ensure the work area is clear before lowering.
14. 14

    Evacuate AC system
    Connect a vacuum pump to the AC service ports using the manifold gauge set. Open both high and low-side valves on the manifold. Run the vacuum pump for a minimum of 30 minutes to remove all air and moisture from the system. The system should pull down to at least 29 inches of mercury (near full vacuum). Close the manifold valves and shut off the vacuum pump. Monitor the vacuum gauge for 10-15 minutes; the vacuum should hold steady, indicating no leaks.
15. 15

    Recharge AC system
    With vacuum holding steady, recharge the system with R-134a refrigerant to the OEM-specified capacity (refer to the underhood AC specification label for the exact charge amount for this vehicle). Add refrigerant through the low-side port with the engine running and AC on maximum. If oil was lost during recovery, replace the amount removed by the recovery machine using the OEM-specified PAG oil viscosity for this compressor (verify viscosity from the compressor label or service manual before adding). Monitor system pressures using the manifold gauge set to ensure proper charge level.

Reassembly

1. Verify all AC line fittings are torqued to specification and properly secured
2. Confirm all mounting clips and brackets are engaged and supporting the hose properly
3. Check that underbody panels are fully reinstalled with all fasteners in place
4. Ensure no AC lines contact moving parts or hot surfaces

Verification

• Start engine and turn AC to maximum cold with fan on high
• Allow system to run for 5-10 minutes and verify cold air output from vents
• Monitor AC pressures with manifold gauges: low side should be 25-35 psi at idle with ambient temperature 70-80°F; high side should be 180-220 psi
• Inspect all newly installed connections for signs of refrigerant oil leakage
• Use electronic leak detector or soap solution to check all fittings for leaks
• Verify compressor engages and cycles normally
• Check that cabin temperature reaches approximately 40-50°F at the center vent with ambient temperature around 75°F

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