I need to do a "top up" on my 2001 Mercedes. It's never had the freon or AC system touched or refilled! Over 17 years on the original R134.
It is finally now starting to not get quite as cold (although still not bad).
I have the gauges and R134, and have added freon to other cars in the past (R12, a while ago), but I don't quite remember the procedure.
I hooked up the gauges and both the high side and low side read low, so I think it's just a matter of adding 134.
Pretty sure I just keep adding until it gets to the high and low pressures on the chart below, correct?
Also, my biggest question, are those numbers on the chart at idle, or at elevated idle, like 2000 rpm? Because of course the numbers change fairly significantly at idle v. higher rpm.
Thanks!
