How to Recharge the AC on a 1994 Jeepby Richard Ristow
Periodically, you will need to recharge a 1994 Jeep's air conditioner. The system runs on R134a freon, and once the R134a level becomes depleted, the system will not generate cold air. The Jeep's air conditioner will be otherwise functional, and there may not even be any major leaks. Adding new freon is not a complex task. No tools, other than a recharging kit, are required, and you can complete the job in the comfort of your own garage.
Set the Jeep's parking brake. Move the shifter into neutral (manual trans) or park (automatic). The recharging process is done with the engine running, so these are basic safety precautions.
Release the hood and prop it open. Within the engine, look for the air conditioner's aluminum tubes. They should be toward the center. You will also notice two pressure connections on the pipes. The one toward the back of the engine is called the high-side port, the one toward the front is the low-side port. The R134a recharging kit will be connected to the low-side port.
Set the recharging kit down in a safe, secure spot. It needs to be away from anything that will move or shift it, once the engine is running. This means any belts or fans could pose a hazard. Leave the kit and get behind the Jeep's steering wheel.
Turn the engine on and watch the thermostat on the Jeep's instrument cluster. Once the engine has warmed up, turn the air conditioning on to its lowest temperature setting. Switch the air conditioner's blower on high.
Put on the safety glasses and the gloves. Return to the engine and the recharging kit. Turn the nozzle atop the can and let the R134a freon flow into the system for one minute. Turn the flow off and let the system rest for a minute. These rest periods will allow the air conditioner to stabilize and circulate the freon as you add it.
Place a thermometer in the Jeep's central air conditioning duct. Monitor the thermometer's readings as you add freon. At its coldest setting, a fully charged air conditioner will cool air to 40 degrees. In hot weather, a charged system will level out anywhere between 40 and 60 degrees. Once the thermometer readings stop falling, the system will be charged.
Remove the thermometer from the air conditioning duct. Detach the recharging kit from the low-side connection. Close the hood, but let the Jeep run for 10 minutes after the process is complete. The running air conditioner will evenly distribute the freon throughout the system. Turn the air conditioner and the engine off.
Store the recharging kit upright in a dark area. Do not take the components apart or release the leftover freon as a means to get rid of it. You can use the leftover R134a later.
- Do not mix R12 with R134a freon. R12 is an older refrigerant used in pre-1984 vehicles. Mixing the two refrigerants will damage your Jeep's air conditioner.
Items you will need
- Safety glasses
- R134a recharging kit