How to Add Freon to a 1992 Chevy Pickupby Lee Sallings
Charging the air conditioning system on a 1992 Chevy pickup is a common home mechanics project. Over time the system will develop small leaks caused by wear of the seals from heat and vibration, and shrinkage during cold weather. Adding freon to the system will keep it working properly without major repairs. However, the 1992 Chevy Truck comes equipped from the factory with an A/C system containing R-12 (Freon) refrigerant. Unlike the later models, equipped with R-134a refrigerant, this system requires a license to be able to purchase the refrigerant and the refrigerant is more expensive than R134a.
Attach the A/C gauge set to the service ports on the truck. The blue (low pressure side hose) attaches to the service port located on the accumulator. The accumulator is the aluminum cylinder shaped device located on the passenger side near the fire wall. The red (high pressure side) hose attaches to the service port located on the small A/C line connecting the condenser to the evaporator located near the accumulator. Close both the blue and red valves on the A/C gauge set.
Start the engine. Set the A/C dash controls to Max A/C and recirculating air. Set the blower speed to medium range. The gauge readings (assuming the system is not to low on refrigerant for the compressor to come on) should be below 30 psi on the low side, and below 150 on the high side.
Attach the can tap to the yellow hose on the gauge assembly. Insert a can of refrigerant into the tap and screw the thumbscrew all the way into the can and then all the way out of the can to open it. With the engine running, and the can of refrigerant open, open the blue valve on the gauge set to allow the refrigerant to be drawn into the system. When the can is empty, close the valve and observe the gauge readings. If the low side reading is between 30 psi and 35 psi, and holding steady, the system is full. If the readings are still low, add more refrigerant until the gauges show the system to be full.
Turn off the engine and allow the pressures shown on the gauges to stabilize. Ensure that both valves are closed on the gauges and remove the hoses from the service ports. Check the system for leaks, and test drive to verify proper operation.
- Use of refrigerant with leak detection dye added will make finding leaks easier.
Things You'll Need
- Refrigerant (2 lbs max)
- A/C gauge set
- Can tap
Lee Sallings is a freelance writer from Fort Worth, Texas. Specializing in website content and design for the automobile enthusiast, he also has many years of experience in the auto repair industry. He has written Web content for eHow, and designed the DIY-Auto-Repair.com website. He began his writing career developing and teaching automotive technical training programs.