I have done this on other cars before, but my Benz is little more temperamental than others ..... so from you experts, I would like to hear how you do it.

To start from the beginning, my AC is not working AND the AC OFF light/button on cosole is ON (I think some call it EC light/button)
The STAR manual mentions to dis-connect the sensor at receiver\dryer when checking the view hole, but I have a fill bottle of R134a with a gauge, so wondering if I need to do that, or if that is the way, I would get compressor to kick in, if low refridgerant "suck" more from my bottle.

Anybody have their process down or ideas to share, besides running car 80 miles to an AC shop and wasting a whole day?

 

im not sure about mb or star procedure but i do recommend that you pull the ac system into vacuum before recharging the system. vacuum for at least 20-30 minutes and bring it down to at least 29"hg vacuum. reason is because the system has excessive air , moisture, and contaminants that need to be removed for ac system to operate properly. if you dont do this critical step your ac will not perform and cause further issues. if you dont have the service equipment i think you should have a shop refill it properly. r-134a freon is really cheap...so a refill service shouldnt cost you much. just my .02 ...goodluck!

 

Are you sure your problem is low Freon? You must check the system's pressures to be sure. Also, there is no need to pull a vacuum if there is still any Freon in the system.

 

very true jud...i was assuming his system is empty . anytime ac system is repaired or has been empty pulling vacuum is very important to get rid of moisture and contaminants.