How to Recharge an R-134a Air Conditioning System
1990-1994 Lexus LS400
If your A/C isn't as cool as it should be then you're probably low on refrigerant....or may have worse problems. Recharging the system is just a notch harder than adding air to your tires. All you need is a can of R-134a with a gauge and you're set. I bought this can at the auto store and it came with the gauge for about $30 (Interdynamics MAC-134). Please note that this is NOT a conversion tutorial, you must ALREADY have an R-134a system to use this tutorial. DO NOT MIX refrigerants!!!
1) In a well ventilated area, start the car and turn the A/C to max cool.
2) Find the low pressure port (circled), unscrew the cap (don't lose it) and connect the hose to the port.
3) Check the gauge and add refridgerant by pressing the button on the can. This pic shows the reading after filling it a bit. Originally it was at 25psi and my system wasn't very cold, now it's nice and cool. When adding, make sure to shake the can periodically and press the button for only 2-3 seconds at a time, then check the gauge to see where you're at. Doing this avoids overfilling.
DO NOT OVERFILL!!!
4) Disconnect the hose, put the cap back on and enjoy the cool air!
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