AC recharge valves...
 

hey all, ive search on this forum and looked everywhere but i can not find the high side valve. i found the low side easly.

Thanks in advance.

edit: sorry, its a 02 c240

As far as I know you need to recharge your system on the low side which usually has a black cap and is located to the right of the engine. To be honest if you can't find the high side valve then you shouldn't have any business with it. Are you trying to recharge with R134a your system? Be careful that if you are trying the high side the refrigerant can explode...

i know what im looking for, i just cant find it. im mechanically inclinded. and yes, i do know i recharge thru the low side, but im not trying to recharge. im trying to diagnose why the AC isnt working by seeing the level of freon. all the fuses are good. so either the freon is too hight or too low.

thanks anyways!

Hissing noise? Ticking? or just plain not cooling off...

just no a/c. clutch isnt engaging. i read the sticky and deff nothing in there.

ok so i looked in my Haynes manual and then took a pic of what they attached the recharge kit to. if someone has actually done this please back me up but i am almost 100 percent sure that this is the low side charging port. wow i just looked at a pic i think i see oil dam it now i have to go back and check.

you are correct, that is the low side. but i need the high side port, does it by anychance have it in the haynes?:rolf:

thanks tho.

sorry i am looking

i am not finding it sorry good luck fixing your car. i will ask a guy that i know works on a lot of Mercedes to see if he has any idea.

Page 29 of this PDF:

http://www.buellwinkle.com/W203HVAC.pdf

Although, I think they may have changed that at some point. I recharged the 134a in my 2005 C230 a few weeks ago, and I think the high side was on the driver's side just a little further down the line from the low side (closer to the driver's side headlight). That's what it looked like at least. I wasn't too concerned about finding it, since I was only checking pressure and recharging on the low side. I did take the cap off just to check it out, and it was a larger diameter valve, which would obviously not fit with a low side measuring/recharge connector.

what's your engine code?

By the way, if its 203.081 then use this
http://i43.tinypic.com/15qrbwo.jpg

Please note that the aircon compressor has no clutch. If the gas pressure in the system is too low the pressure safety switch will not allow the unit to run.

How about doing a write up DIY?
I've never charged my AC but it takes a long time to cool...
it would be great to read on something from someone who has done it.
https://mbworld.org/forums/attachmen...1&d=1242679210

Here for previous on this topic.

https://mbworld.org/forums/c-class-w...ressure+switch

As far I as I know you only check the freon level in the low side. Otherwise the measure thingy won't fit.

I probably should have taken some pictures, but it really wasn't hard at all. Easier/shorter than an oil change, really. And this is from a guy with no mechanical abilities who had never even looked at an automotive AC system before. I just read the instruction sheet that came with the hose/gauge and can. The only issue was finding the right valve, which was easier thanks to Buellwinkle's handy PDF.

I did have a little confusion at first, because like I said, in my car (2005 C230), the high side valve was just a little further along the line (toward the front of the car) instead of on top of the radiator like that diagram shows. But thanks to those really smart automotive engineer guys, I quickly deduced that the high side was not the one I wanted because the high side valve is bigger (wider in diameter). The hose/gauge couldn't be connected to it. (In my defense, I did actually try the low side first, and it worked, but then I saw the cap for the high side, and I started to wonder if there were somehow TWO low side valves for some reason. The incompatibility of the connector to the second/high side valve confirmed it for me. I'm really smart, by the way.)

I assume that maybe they make them different sizes so that automotive ignoramuses like me don't severely frostbite, maim and/or kill ourselves by hooking up a highly pressurized can of 134a to the wrong valve. With a bigger valve, it's physically impossible no matter how inexperienced/stupid one might be. Believe me, I'm glad they seem to make certain things like this idiotproof.

Yeah. What Fanito said. Just a lot less wordy than me.

I'm jealous that you coined the term "measure thingy." That is definitely something I would normally come up with. Damn.

lol :hammer:

haha, thanks guys. found the valve!

oh and the "measure thingy" you refer to is prob the manifold guage.

the reading from the high side is to see if theres a clog at the expansion valve or not, and many other reasons. perhaps i will do a write up if i end up doing a recharge.

what's the climatronic unit look like? my wife's 05 230K doesn't cool, but it does blow air just fine. i tried the reset to no effect.

Its nearthe. Radiator