Hi Everyone,
I am curious what the AC cooling temperature should be on an 86 560sl. I did a dianostic test myself and this is what I found. At idle the ac is cooling to 58degrees(high pressure is 125 and low is 25)..at 2000rpm the AC cools to 540(high pressure is the same)...first question..is this a normal cooling temperature? and 2nd..when the ac turns on and the engine is at 2000rpm..the low pressure dips all the way to zero and then works its way back to 25...I have heard that this may be my expansion valve...If my AC is working as stated above should I even worry about it? Oh yes, the above was tested on an 80 degree day.

Thanks for your advice!

Have a tech check the level of the freon.

If you do it yourself, the readings should be as follows.

Clean the window on the sight glass of the drier.

Turn on the A>C and look into the glass. IF bubbles are seen, the system is low/ The bubbles should come in for a few seconds then the glass should clear for a while.

This cycle is the key to a properly charged system.