If your 1998 Toyota 4Runner is running low on refrigerant, you will notice that your air-conditioning system is not as cool as it was in the past. It is important to note that there are a variety of other components in your air-conditioning system. If recharging the refrigerant does not work, you may have to repair or replace one or more other air-conditioning components, including the compressor, condenser, evaporator or accumulator.
Locate the 4Runner's air-conditioning condenser, which is under the hood and close to the upper-left part of the engine. It looks like a smaller version of the radiator grill. Locate the compressor, which is a cylindrical unit with the air-conditioning belt attached to a pulley. Look for the high- and low-side service-fitting valves, which are marked with an H and an L, respectively. The high- and low-side valves are 13 mm and 16 mm quick-disconnect valve types. The low-side fitting is near the hose that connects the compressor and the accumulator. The high-side fitting is near the hose that connects the compressor to the condenser.
Connect the output hose for the refrigerant recharge kit to the service nozzle on the refrigerant can. Slowly rotate the hose, tightening it around the nozzle, until the can is punctured. Bleed air from the hose by turning the output valve on the refrigerant can until you hear a release of air from the can. Close the valve.
Screw on the hose from the refrigerant kit to the Toyota's air-conditioning system, connecting the service hose to the low-side fitting. If your kit comes with a high-pressure gauge, connect that to the high-side fitting. It is not mandatory to have a high-pressure gauge, although it may help in determining when your air-conditioning system is fully recharged.
Turn on your 4Runner, and select the highest setting for your air-conditioning system. Rotate the valve on your recharge kit, releasing the refrigerant through the service hose. It is also helpful to have a partner sit inside your 4Runner to feel the temperature of the air coming out of the vents. When the system is fully recharged, the vents should be piping out cold air. If your recharge kit does not have any gauges, you will need to turn off the refrigerant recharge valve as soon as the air turns cold. Otherwise, you may overcharge your air-conditioning system and cause seals and gaskets to blow out. If you have a low-pressure gauge, it should read between 25 and 40 psi, pounds per square inch. If you are using a high-pressure gauge in addition to the low-pressure gauge, the high-pressure gauge should read between 225 and 250 psi.
Turn the engine off, and close the valve on the refrigerant recharge kit before disconnecting it from the low-side service fitting.
