AC Hose - High Side

Replace the high-side AC hose on a 2014 Ram 2500 with 6.7L Cummins diesel engine, including refrigerant recovery, hose replacement, and system recharge.

Warnings

Tools required

Parts

• AC High Side Hose Assembly × 1 — Use OEM specification
• AC Line O-rings × 4 — Use OEM specification
• PAG oil for AC system × 1 — Use manufacturer specified viscosity

Fluids

• R-134a Refrigerant

Preparation

1. Park vehicle on level surface and engage parking brake
2. Allow engine to cool completely (minimum 2 hours if recently operated)
3. Disconnect negative battery terminal to prevent compressor clutch engagement
4. Gather all required tools and replacement parts
5. Verify AC machine is functioning properly and has full recovery tank capacity

Procedure

1. 1

   Recover refrigerant from AC system
   Connect AC recovery machine to service ports (low and high side). Follow machine instructions to completely recover all refrigerant from the system. Record the amount of refrigerant and oil recovered. This process typically takes 15-30 minutes. Ensure system reaches complete vacuum indicating full recovery.
2. 2

   Access high-side hose at condenser
   Open hood and locate the high-side AC line connection at the condenser (front of vehicle, ahead of radiator). Remove any plastic covers or shields that obstruct access to the line fittings. The high-side line runs from the compressor discharge port to the condenser inlet.
3. 3

   Disconnect high-side line at condenser
   Using appropriate line wrench, carefully loosen the fitting connecting the high-side hose to the condenser. Hold the condenser fitting stationary with a backup wrench to prevent twisting the condenser tubes. Remove the bolt or spring lock coupling (depending on connection type). Remove and discard old O-rings from the fitting.
4. 4

   Access compressor discharge connection
   Locate the compressor on the passenger side of the engine. The high-side line connects to the discharge port on top of the compressor. You may need to remove the engine cover or air intake components for better access. Remove any fasteners securing the line to mounting brackets along its route.
5. 5

   Disconnect high-side line at compressor
   Using line wrench, carefully loosen and remove the fitting at the compressor discharge port. Use a backup wrench on the compressor port to prevent damage. Once loose, carefully guide the line away from the compressor. Cap the compressor port immediately to prevent moisture and debris entry. Remove and discard old O-rings.
6. 6

   Remove high-side hose assembly
   Trace the entire hose route and remove any remaining mounting brackets or clips securing the line to the vehicle. Carefully extract the old high-side hose assembly from the engine bay, noting the routing path for installation of the replacement. Inspect mounting brackets for damage.
7. 7

   Prepare new high-side hose
   Unpack new high-side hose assembly and verify it matches the original in length and fitting configuration. Install new O-rings on both ends of the new hose (condenser and compressor connections). Lightly coat new O-rings with appropriate PAG oil (use same viscosity as system specification). Add the recommended amount of fresh PAG oil to the new hose (typically 1-2 oz) to replace oil lost with old hose.
8. 8

   Install new hose at compressor
   Route the new high-side hose along the original path from condenser area to compressor. Remove cap from compressor discharge port. Align the lubricated fitting with the compressor port and hand-thread carefully to avoid cross-threading. Once hand-tight, use torque wrench and line wrench to tighten to specification.
   Torque spec

   AC Line Fittings20 Nm (15 lb-ft)
9. 9

   Install new hose at condenser
   Guide the condenser end of the new hose into position. Ensure the lubricated O-rings are properly seated. Hand-thread the fitting onto the condenser port, being careful not to cross-thread. Use backup wrench on condenser fitting and torque wrench to tighten to specification.
   Torque spec

   AC Line Fittings20 Nm (15 lb-ft)
10. 10

    Secure hose routing and brackets
    Reinstall all mounting brackets and clips along the hose route to secure the line and prevent vibration or contact with hot engine components. Ensure the hose does not contact sharp edges, moving parts, or exhaust components. Verify adequate clearance throughout the routing path.
11. 11

    Evacuate AC system
    Connect AC machine to service ports. Run vacuum pump to evacuate the system to at least 29 inches of mercury (Hg) vacuum. Hold vacuum for minimum 30 minutes (45 minutes preferred in humid conditions) to remove all air and moisture. Monitor for vacuum decay which would indicate a leak.
12. 12

    Recharge AC system
    Using AC machine, recharge system with the amount of R-134a refrigerant that was recovered (typically between 2.0-2.5 lbs for this system, verify on underhood label). Add any additional PAG oil if required per machine recommendations. Follow machine prompts to complete recharge process.

Reassembly

1. Reinstall any engine covers, air intake components, or shields removed for access
2. Reconnect negative battery terminal
3. Start engine and verify compressor clutch engages when AC is activated
4. Check all connection points for signs of refrigerant leaks using leak detector or soap solution

Verification

• Start engine and turn AC to maximum cold setting with blower on high
• Allow system to run for 5-10 minutes and verify cold air output from vents (typically 40-50°F)
• With engine running and AC on, visually inspect both hose connections for signs of oil weeping or frost (indicating leaks)
• Check system pressures: High side should read approximately 225-250 PSI at 80°F ambient (varies with temperature)
• Verify compressor cycles properly and clutch engagement is smooth
• Use electronic leak detector around all fittings to confirm no refrigerant leaks
• Test drive vehicle and confirm AC performance under load conditions

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