Over time your Chevy Tahoe’s air conditioner may begin to blow warm air. This is a sign that it needs to be recharged with refrigerant. Having a mechanic recharge your air conditioner can be expensive; instead you can purchase a can of R134a refrigerant that includes a hose and recharge the system yourself. Once you have recharged it, you should have cool air in your car once again.
Allow the engine to cool for at least 20 minutes before you begin any work under the hood.
Locate the service fittings on your Tahoe’s air-conditioning system. You may need to refer to your owner's manual. The Tahoe has two fittings. The low side fitting is on the suction hose running from the accumulator to the compressor. The high side fitting is on the hose from the compressor to the condenser.
Connect the recharge service hose and valve to the refrigerant can. You can purchase the R134a refrigerant at any auto shop. Instructions are on the side of the refrigerant can. Turn the valve on; this will puncture the top of the can and release a bit of air and coolant. Close the valve to prevent losing extra refrigerant.
Connect the service hose to the low side fitting. Hold the can upright to keep the refrigerant from getting into the hose.
Start the Tahoe’s engine and turn the air conditioner on to the max. You may want to have another person do this step so you can monitor the refrigerant. Open the service hose valve to allow the refrigerant vapor to flow into the system. If you have a second person helping you, he should feel the air getting colder.
Close the hose valve and shut off the engine when you are done charging the system. You can charge the system until the refrigerant is empty in the can or until the air does not get any colder. Once the valve is closed, disconnect it from the low side fitting. Repeat this process anytime your air conditioner needs to be recharged.