How to Add Freon to a 1999 Pontiac Grand Prix 3800

Have you noticed your car's air conditioning is taking longer and longer to cool the interior of your vehicle? This is only the beginning of a progressing problem. As time goes by, the car will eventually blow little to no cool air, an indication that the air conditioning system in your car needs attention.

If you are experiencing this problem in a newer car, it’s probably best to take the car to a certified mechanic to diagnose the problem. If it’s an older car, the system probably needs a freon recharge.

For those who have the confidence, aptitude, and desire to fix things themselves, recharging the air conditioning system in your car is a fairly straight forward operation.

To recharge the air conditioning system on a 1999 Pontiac Grand Prix 3800, use the steps outlined below. These can be used as a reference or general overview, but they are no substitute for a good maintenance manual.

It is also important to follow all safety procedures outlined in the vehicle's owners and maintenance manual. If these procedures are not followed, the result may be serious injury or even death. This is a pressurized system, so precautions should be taken when performing maintenance.

1. Obtain a r134a recharge kit. Read and follow all the instructions that come with the kit.

2. Identify the location of the low pressure service port.

3. Start the car, roll the windows down, and turn the A/C to max. Let the car run for approximately three minutes.

4. Use a temperature gauge to determine the temperature coming out of the center vent. If the system is fully charged, the temperature should be around 40 degrees. If this is the case, your A/C is still running strong and there is no need to add freon. If the gauge reads 40 degrees or above, continue with the steps below.

5. Remove the cap from the low pressure service port.

6. Connect the quick connect fitting, hose, and gauge to this port. Take a reading from the gauge. You want the gauge to indicate low pressure.

8. Disconnect quick connect fitting.

7. Add the can of r134a freon to the hose. Reconnect the quick connect fitting, hose, and gauge to the low pressure service port.

8. Release freon into system, following the instructions provided with the recharge kit. Keep a close eye on the gauge while moving the can back and forth every few seconds. The system should be charged up to the appropriate pressure for outside or ambient temperature. Never overcharge the system.

9. Once the system is charged, disconnect the quick disconnect fitting and replace the cap on the low side pressure service port.

10. Return to the interior and place the temperature gauge in the center vent. The air should now be blowing at or around 40 degrees, and the temperature in the car should feel noticeably cooler.