Okay, I have read all the posts. I am a novice mechanic now with the attitude that I have nothing to lose. Repair bills are too expensive. Worst case scenario, after I try and **** it up, I'll take it to the pros

Here's the issue:
126 1991 300SEL
A/c works okay if its <80 degrees outside
Now in Dallas, its 103-104 degrees daily
I'm tired of walking into work with a shirt with a wet back

The compressor seems to work
I took the test, now I can by R12

I found the low side recharge port. Where do I hook up the high side of the manifold gauge. What should the low and high side pressures be. Are the expansion valve in the same place as a 300D in the passenger compartment foot well. Should I just add a little freon and see how it works? Should I disconnect everything and flush everything and fill the whole system up? Do I need to add more oil or just freon?

Please help?
I have the mercedes CD...it sucks!

email: raghu@athre.com

PS forgot to add this to the post. If anyone wants, I can give my phone number to their email to discuss since this is a lot of ?'s

If you have a set of gauges and you want to add R-12, leave the high side gauge turned off and just hook up the low side. I'm assuming you know how to connect the R-12 jug/can to the gauge set. Before turning on the low side valve to add the freon, look at the sight glass on the receiver/drier, you should see cloudy bubbles. If so, start adding freon to the system while monitoring the sight glass. When it turns clear, turn of the freon and you're done. Also, you may need to increase the idle while you're adding freon...I do it myself at the throttle housing location but you may want to have someone sit in the car to do it.
It sounds like you're about a pound low on R-12. Just take it slow and it should work fine.

The low side should be around thirty pounds at fast idle, but when you turn on the valve to add freon, the pressure will jump up due to the pressure in the freon jug/can. When you turn the valve off, the low side will settle back down to operating pressure.

Hope this helps,

Dave

call me if you wish and i can answer all your questions.214-9567007 david poole european performance dallas tx.