AC Receiver/Drier

Replace the AC receiver/drier to remove moisture and debris from the air conditioning system on a 1970 AMC Rebel Machine with 390ci V8.

Warnings

Tools required

Parts

• AC receiver/drier assembly × 1 — Use OEM specification or aftermarket equivalent for 1970 AMC with factory AC
• AC line O-rings × 2 — Use refrigerant-compatible O-rings for R-12 or R-134a conversion
• Refrigerant oil × 1 — Mineral oil for R-12 or PAG oil for R-134a conversion

Fluids

• R-12 refrigerant (or R-134a if converted)

Preparation

1. Park vehicle on level surface and engage parking brake
2. Allow engine to cool completely if recently operated
3. Verify AC system type (R-12 original or R-134a if previously converted)
4. Gather all necessary EPA-certified refrigerant recovery equipment
5. Locate receiver/drier mounted on firewall or inner fender on passenger side near condenser outlet

Procedure

1. 1

   Recover refrigerant from system
   Connect refrigerant recovery machine to both high and low side service ports. Follow recovery machine manufacturer instructions to completely evacuate all refrigerant from the AC system. Record amount of refrigerant recovered for recharge reference. Ensure recovery cylinder is properly rated and not overfilled.
   ⚠️Only EPA-certified technicians may recover refrigerant. Venting R-12 to atmosphere is illegal and subject to federal fines.
2. 2

   Disconnect battery ground cable
   Disconnect negative battery cable to prevent electrical issues while working near engine compartment components. Isolate cable end away from battery terminal.
3. 3

   Remove inlet line from receiver/drier
   Using appropriate line wrench, disconnect the inlet line from the receiver/drier (coming from condenser). This is typically the upper connection. Support the receiver/drier body with one hand while loosening the fitting to prevent twisting the lines. Cap or plug the open line immediately to prevent moisture and debris entry.
   ⚠Use line wrenches to prevent rounding off soft refrigerant line fittings. Do not use standard open-end wrenches.
4. 4

   Remove outlet line from receiver/drier
   Using line wrench, disconnect the outlet line from receiver/drier (going to evaporator). This is typically the lower connection. Support the receiver/drier to prevent line damage. Immediately cap or plug the open line to prevent contamination. Note the position and routing of both lines for reinstallation.
5. 5

   Remove receiver/drier mounting bracket
   Remove the mounting bracket bolt(s) securing the receiver/drier to the firewall or inner fender. The 1970 AMC typically uses a single U-bolt clamp or strap bracket. Keep hardware for reinstallation. Carefully remove the receiver/drier assembly from the vehicle.
6. 6

   Inspect old receiver/drier and lines
   Examine the old receiver/drier for physical damage, oil residue indicating leaks, or corrosion. Check the condition of refrigerant lines and fittings for damage or wear. Inspect O-rings on line fittings and replace if hardened, cracked, or damaged. Pour out old receiver/drier and check for excessive debris or metal particles that may indicate compressor failure.
7. 7

   Prepare new receiver/drier
   Remove shipping caps from new receiver/drier only immediately before installation to minimize moisture exposure. Add the appropriate amount of refrigerant oil to the new receiver/drier as specified by manufacturer (typically 1-2 ounces). Use mineral oil for R-12 systems or appropriate PAG oil if converting to R-134a. Do not leave receiver/drier uncapped for more than 15 minutes.
8. 8

   Install new receiver/drier
   Position new receiver/drier in mounting bracket location, ensuring proper orientation with inlet at top and outlet at bottom. Install mounting bracket and secure with original hardware. Ensure receiver/drier is firmly mounted but bracket is not over-tightened to avoid crushing the canister. Verify adequate clearance from engine components and belts.
9. 9

   Connect refrigerant lines
   Install new O-rings on both refrigerant line fittings, lightly lubricating with refrigerant oil. Connect inlet line (from condenser) to upper receiver/drier port and hand-tighten. Connect outlet line (to evaporator) to lower port and hand-tighten. Using line wrenches, tighten both fittings snugly. Do not over-torque as this can damage the soft aluminum fittings.
10. 10

    Evacuate AC system
    Connect vacuum pump to AC system service ports. Evacuate system to 29-30 inches of mercury vacuum for minimum 30-45 minutes to remove all moisture and air. Close service valves and observe vacuum gauge for 10 minutes - vacuum should hold steady indicating no leaks. If vacuum drops, locate and repair leak before proceeding.
11. 11

    Recharge AC system
    Using refrigerant manifold gauges and appropriate refrigerant (R-12 original or R-134a if converted), recharge system to factory specification. For 1970 AMC Rebel with factory AC, typical charge is approximately 3 pounds R-12 (or 80-85% of that amount if using R-134a). Charge through low-side port only with engine running and AC on maximum. Monitor gauges and add refrigerant until proper pressures are achieved.
12. 12

    Reconnect battery and test system
    Reconnect negative battery cable. Start engine and turn AC to maximum cold and high blower. Allow system to run for 5-10 minutes. Check all connections at receiver/drier for leaks using leak detector or soap solution. Verify proper compressor cycling and cold air output from vents.

Reassembly

1. Ensure all refrigerant line connections are tight and leak-free
2. Verify receiver/drier mounting bracket is secure
3. Confirm proper refrigerant charge and system operation
4. Clean any spilled refrigerant oil from engine compartment components

Verification

• Check that AC system produces cold air at vents (typically 40-50°F cooler than ambient)
• Verify compressor clutch engages and cycles properly
• Inspect all connections at receiver/drier for refrigerant leaks using electronic leak detector or soap solution
• Confirm proper high and low side pressures with manifold gauge set (low side 25-35 PSI, high side 200-250 PSI at 75°F ambient for R-12)
• Listen for unusual noises from compressor or refrigerant lines indicating blockage or loose components
• Verify sight glass (if equipped) shows clear refrigerant flow without excessive bubbles

More procedures for this vehicle