My 1997 C280 wasn't cooling like I thought it should, so I decided to add a can of 134a to the system. I added the freon and now the AC system is not cooling at all. I then evacuated the system, and the vacuum held at 29" of mercury for several hours.
I put new freon in the system and the gauge immediately went to over 100 psi on the low side. Then the receiver drier started blowing out a gas which is probably freon, out of a brass port on one side of the drier.
I have done auto air conditioning for several years, but have never had any problem like this. I have ALLDATA, which hasn't been much help.

At this point I have no air conditioning.

Is there a certain procedure for recharging the AC in a Mercedes C280? I'm at a loss, and ANY help is greatly appreciated.
Thank You

 

The brass fitting on the side of the reciever drier is an over pressure pop-off valve.

Something is definately wrong with your system, how much gas did you put in? Did you charge on the low or high side? How's your TX valve?

 

I charged on the low side. What is the TX valve?

 

TX means thermal expansion valve.

How much gas did you put in after vaccuming it down? did you put the gas in with the compressor running or engine off? if with the engine off, did you turn the compressor over by hand after you gassed it?

Do you have A/C gauges?

 

Thanks. Now I know what a TX valve is. I have gauges. I put 1 1/2 cans in, with the engine running. This is the way I have recharged all my vehicles for 10 yrs. Do you charge a Mercedes with the engine off?

 

having AC problem with my 1997 c280.. can you tell me where the low side valve is? I took it to the dealer and they told me I gotta pay about 1000 to fix the problem, I'm gonna try to fill the gas and add some super seal to it.
my car has a lot of miles and I bought it for $2000 spending $1000 seems un-logical. how did your AC problem come out? any advise?

 

The low side is under the grill on the right. You have to remove the grill to see it.

 

How do I replace receivervdrier in c280?