AC system recharge on the 2012 Tesla Roadster, which uses a conventional R134a refrigerant circuit (not the heat-pump architecture of later Teslas). This is a straightforward evacuate-and-recharge through the service ports.

Warnings

Tools required

Parts

• R134a service port caps (replace if missing/damaged) × 2 — generic R134a high/low side caps

Fluids

• R134a refrigerant — refer to under-hood AC label for system charge weight
• PAG oil — type and quantity per AC label / Roadster service manual (only if system was opened or low)

Preparation

1. Park on level ground, place in P (or in gear with parking brake fully set on manual-equipped early Roadsters), engage parking brake.
2. Exit ALL doors with the key fob away from the vehicle. Wait at least 2 minutes for HV systems to fully de-energize, even on this non-HV job.
3. Disconnect the 12V low-voltage auxiliary battery before working in the front compartment. On the Roadster, the 12V auxiliary battery is in the front (frunk) area — see Roadster Owner's Manual for exact location and disconnect sequence.
4. DO NOT touch, cut, or pierce ANY orange cable — these are high-voltage and lethal.
5. If at any point you encounter an orange cable, an HV component, or are unsure if a system is de-energized: STOP and consult a Tesla-certified technician.
6. Locate the AC service ports. On the Roadster these are accessed in the front compartment area on the AC lines. Confirm refrigerant type (R134a) and total charge weight from the AC system decal.
7. Verify the compressor and condenser are physically intact and that no obvious leaks (oil staining at fittings) are present before recharging.

Procedure

1. 1

   Inspect AC system condition
   Open the front compartment. Visually inspect AC lines, condenser, and accessible fittings for oil residue (a sign of refrigerant leaks). Inspect the condenser fins for road debris damage. If significant oil staining or damage is found, do not proceed with a simple recharge — repair the leak first.
2. 2

   Connect manifold gauges / recovery machine
   Remove the high-side and low-side service port caps. Connect the recovery machine's high-side (smaller diameter) and low-side (larger diameter) couplers to the matching ports. Ensure couplers are fully seated and valves closed.
   ⚠Never reverse high and low side fittings. The Roadster uses standard R134a quick-connect sizes which prevent this, but do not force a coupler.
3. 3

   Recover any remaining refrigerant
   Run the recovery machine's recover cycle to capture any refrigerant currently in the system into the recovery tank. Note the recovered weight — this helps diagnose whether the system was undercharged, overcharged, or empty (leak).
   ℹ️Venting refrigerant to atmosphere is illegal in most jurisdictions and requires EPA Section 609 certification in the US.
4. 4

   Evacuate the system
   Pull a vacuum on the system to at least 29 inHg (or per machine spec) and hold for a minimum of 30 minutes. Close the valves and observe — vacuum should hold steady. A rising vacuum reading indicates a leak or moisture; do not proceed until the system holds vacuum.
   ⚠Skipping or shortening evacuation traps moisture in the system, which forms acids and destroys the compressor and desiccant.
5. 5

   Add PAG oil if required
   Only add PAG oil if the system was opened, a component was replaced, or oil was lost with the recovered refrigerant. Type and quantity must match the AC system decal or Roadster Service Manual specification — do not guess. Skip this step for a routine top-off recharge.
6. 6

   Charge the system with R134a
   Charge the system by weight to the exact specification listed on the under-hood AC decal. Do NOT charge by pressure alone — the Roadster's specified charge is by weight. Use the recovery/recharge machine's automated charge cycle for accuracy.
   ⚠Overcharging causes high head pressures and can damage the compressor. Undercharging causes poor cooling and starves the compressor of lubricating oil.
7. 7

   Disconnect couplers and verify fittings
   Once charge is complete, close machine valves and disconnect the high and low side couplers. Inspect the Schrader valves at the service ports for any sign of refrigerant weeping. Reinstall the service port caps (the caps themselves are part of the seal — do not omit them).
8. 8

   Leak check
   With the system charged, use an electronic leak detector or UV dye light (if dye is in the system) to scan all accessible fittings, the compressor shaft seal, condenser, and evaporator drain for leaks.

Reassembly

1. Confirm both service port caps are installed and snug (hand-tight plus snug — these are not torqued fasteners).
2. If any AC line fittings were opened during diagnosis, torque to the AC Line Fittings specification with new O-rings lubricated with PAG oil.
3. Reconnect the 12V low-voltage battery.
4. Close the front compartment.

Verification

• Start the vehicle and turn AC to maximum cooling, highest fan speed, recirculate ON, with doors closed.
• After 5–10 minutes of operation, measure center vent temperature with a digital thermometer — expect approximately 38–50°F (3–10°C) at the vent depending on ambient temperature and humidity.
• Verify the compressor cycles normally and there are no unusual noises from the compressor or expansion valve.
• Confirm high and low side pressures are within R134a normal operating ranges for the current ambient temperature.
• Note: The 2012 Roadster has no Tesla Toolbox-readable AC diagnostic interface comparable to modern Teslas — verification is by physical measurement only.
• While in the system, consider noting cabin air filter condition (Tesla recommends replacement every 2 years on modern vehicles; the Roadster's filter, if equipped, should be inspected on a similar interval).

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