How do you recharge the air conditioner on a Mercedes?

Answer 1

It depends on the year of the Mercedes.

If the car is newer than about 1992 (in Mercedes' case) then it uses what's called R-134a refrigerant. This is an environmentally safe refrigerant that won't deplete the o-zone layer.

If the car is older than about 1992, it originally used R-12 refrigerant. R-12 is more effective at cooling than R-134a, but when vented to the atmosphere, it depletes the o-zone layer. Most pre-1992 Mercedes that have had working A/C in the past 10 years or so have already been converted to R-134a. If not, you will have to convert before you recharge. There should be a label under the hood specifying what refrigerant the car accepts and if it was retrofitted.

Now then. Auto parts stores and even Wal-Mart carry AC Recharge Kits. They contain the can of refrigerant, a hose to hook up to your A/C system and sometimes a gauge to tell you the pressure. (These are the one's to look for because if you overcharge your AC system, the compressor may prematurely fail)

Following the directions on the can, open the hood, start the car and turn on your climate control to its coldest setting. If you have an AC button or setting, use it. Turn the fan speed to its highest setting, also.

Under the hood you should see about 2 or more metal lines that have little nipples on them with covers. Sometimes the covers are blue, red or black. Also, sometimes they are labelled L (for low-pressure) and H (for high-pressure). You want to use the low-pressure port and hook up your can of refrigerant to it. Follow the directions on the can as far as position of the can, shaking the can, etc. and how long you need the can hooked up. After the AC is charged, disconnect the hose and put the cover back on the fitting. Check inside the car, you should have cold air coming out of the vents. Depending on how long you have cold air for (days, months, etc.) determines how bad your leak is.

Air Conditioning Refrigerant doesn't wear out or get used. It's supposed to be in the system for the life of the car, but leaks develop and it escapes to the atmosphere, therefore, no cold air conditioning.

If you have a severe leak, you might want to try and run a can of AC Stop Leak through the system before you charge it with refrigerant.

I hope this very long post helps you out!