How to Recharge an Air Conditioner on a 2000 Lincoln Continental

Remove the caps on the Schrader valves, used for charging on the high- and low-pressure refrigerant lines. These lines are located on the passenger's side fender well. The smaller of the two lines is the high-pressure line, and the larger of the two is the suction, or low-pressure line. The high pressure line will have a red cap and the low pressure line a blue cap.

Connect the refrigerant gauges to the system -- the blue hose to the larger, low-pressure line Schrader, and the red to the smaller, high-pressure line Shrader. Turn the knobs on each connector clockwise to open.

Connect the yellow hose from the gauges to the vacuum port on the top of the vacuum pump. Plug the vacuum pump in and turn it on.

Open both the blue and red valves on the gauges. Allow the system to evacuate until the blue, low-pressure gauge shows approximately 30 inches of vacuum. Notice that the dial has red numbers on the opposite side of the 0, in increments to 30 -- this represents the amount of vacuum in the system. When a proper vacuum is established, close the valves on the manifold gauges and shut off the vacuum pump. Watch the blue gauge vacuum reading for a minute or two, to see if it looses vacuum, indicating a leak in the system. If the gauge stays on 30 inches, there is no leak. If the needle drops off to 0, it has lost its vacuum, indicating a leak.

Repair the leak if the vacuum has dropped off. In order to do this you must go over every connection and check for tightness. If everything is tight, it is time to take the car to a shop to have it tested. The only way to test it further is to charge the system long enough to use a leak detector to locate the leak (or put leak detector dye into the system; the dye can be detected with ultra-violet light). The Freon must then be reclaimed in order to effect a repair. It is not only illegal, but also irresponsible to release fluorocarbons into the atmosphere.

Begin to vacuum the system again, now that it has been confirmed that there are no leaks. Turn the pump on, open the manifold valves and allow the system to remain in a vacuum for 30 minutes. Moisture evaporates much faster in a vacuum, so this will give the system enough time to purge itself of all moisture and air. The air must be removed because the system can't be charged as long as air is in the system. Two objects occupying the same space at the same time does not work.

Close the manifold valves on the gauges and shut off the vacuum pump. Remove the yellow hose from the pump. Connect the yellow gauge hose to a bottle of R-134. Open the valve on the can of Freon and loosen the yellow hose connection slightly next to the gauges to allow the air in the hose to leak out. When Freon mist begins to emerge from the loose hose connection, tighten the hose connection.

Charge the system by opening the blue, low-side valve only and allow the first can to discharge into the system. This will supply enough pressure to close the low-side switch to activate the compressor when the engine is started and the air turned on. When the can feels empty, close the blue, low-side valve. Remove the can and replace it with another full can. Bleed the air out again by opening the valve on the can and loosening the top yellow hose connector until Freon emerges. This is where an air conditioning system can be dangerous. Never, under any circumstances open the red, high-side valve when pressure is in the system. The can only has approximately 40 pounds of pressure, whereas the red, high-side line has 230 plus. This pressure will feed back immediately to the can and explode the can violently, causing bodily injury or death.

Start the engine and turn the air conditioning on, and the fan on high. Open the blue, low-side valve and watch the gauges. The system will be full when the low-side gauge shows approximately 30 PSI and the high-side red gauge shows 230 to 250 PSI. The gauge readings will vary slightly, according to the outside temperature. Watch the gauges for these numbers and place your hand on the accumulator. When the system is almost fully charged, you will feel the accumulator very suddenly drop in temperature to a chill. If this happens at 25 PSI on the low side and 210 PSI on the high side, continue until the pressures reach the prescribed range.

Close the blue, low-side valve and shut the engine off. Remove the hoses from the Shrader valves and install the caps on these valves.