1. Purchase an A/C recharge kit. This kit will include a can of refrigerant, a charging hose, and a pressure gauge.
2. Locate the low-pressure service port. On the 2004 Lincoln LS, the low-pressure service port is located on the passenger side of the engine compartment, near the firewall. It is a small, brass fitting with a blue cap.
3. Connect the charging hose to the low-pressure service port. Screw the charging hose onto the low-pressure service port until it is snug.
4. Open the refrigerant can. Puncture the seal on the refrigerant can with the included can opener.
5. Charge the A/C system. Slowly open the valve on the charging hose to allow the refrigerant to flow into the system. Monitor the pressure gauge on the charging hose. The pressure should not exceed 40 psi.
6. Continue charging the system until the pressure gauge reads between 30 and 35 psi. Once the desired pressure is reached, close the valve on the charging hose.
7. Disconnect the charging hose from the low-pressure service port. Unscrew the charging hose from the low-pressure service port.
8. Replace the cap on the low-pressure service port. Screw the cap back onto the low-pressure service port until it is snug.
Note: Recharging the A/C system can be dangerous if not done properly. If you are not comfortable performing this task, it is best to have it done by a qualified mechanic.
