Follow the steps below to install R-134a refrigerant in your 1994 GMC Jimmy:
1. Park the vehicle in a shady spot and turn off the engine.
2. Open the hood and locate the low-pressure service port. It is usually located on the passenger side of the engine compartment, near the firewall.
3. Remove the cap from the low-pressure service port.
4. Attach the R-134a refrigerant charging hose to the low-pressure service port.
5. Start the engine and let it run for a few minutes.
6. Turn on the air conditioner.
7. Slowly open the refrigerant charging valve on the charging hose.
8. Monitor the pressure on the gauges. The pressure should rise as the refrigerant is added to the system.
9. Continue to add refrigerant until the pressure reaches the recommended level. The recommended pressure is usually between 35 and 55 psi.
10. Close the refrigerant charging valve.
11. Remove the charging hose from the low-pressure service port.
12. Replace the cap on the low-pressure service port.
Make sure to read the instructions on the R-134a refrigerant can carefully before you start charging the system. If you are not comfortable charging the refrigerant yourself, you can take your vehicle to a qualified auto repair shop to have it done.
