98 W210 won't take AC recharge?

[John Doe]

I recharged my AC about two years ago, and it has been fine ever since, until now. It has sat up for several months with only periodic driving. I hooked a can of 134a up to the low pressure side (in front of the brake booster) and the pressure seems to backflow into the can--scary.

I searched tech help and DD and have reviewed all A/C posts and can't see where others have had this issue. Any ideas? Bad can of freon? Bad hose kit (its old--but would be a cheap alternative to something catastrophic).

Thanks!

[TX76513]

What are your High and Low Pressure readings? or Are you just working from the can?

[John Doe]

Originally Posted by TX76513

What are your High and Low Pressure readings? or Are you just working from the can?

Might as well be working from the can (using an old hose I had with a crappy gauge). My real set of gauges is 800 mi. away

[TX76513]

I hear ya! I have been real anal about recovering freon to see how much is in there and then vacuum down and reinstall proper weight. Kids solution to colder air was always Add, not a good idea. You over in this part of woods or on R coast?

[John Doe]

Originally Posted by TX76513

I hear ya! I have been real anal about recovering freon to see how much is in there and then vacuum down and reinstall proper weight. Kids solution to colder air was always Add, not a good idea. You over in this part of woods or on R coast?

In VA. My plumber is coming over tomorrow, and he's pretty good w/cars. If he can't fix it, I'll take it to Richmond. I don't fool with cars enough to evac/weigh, ect....I usually don't drive here, but have decided to leave this car here permanently, so I drove up.

[KarTek]

How do you know it's back-flowing? You are charging while compressor is engaged and the engine is running, right? Is the can getting cold?

Of course, using the gauges is the recommended procedure...

[John Doe]

Originally Posted by KarTek

How do you know it's back-flowing? You are charging while compressor is engaged and the engine is running, right? Is the can getting cold?

Of course, using the gauges is the recommended procedure...

One of my neighbors apparently owns a small rural Chevy dealership and had his 'mobile service' truck over to change the oil in his boat, and they hooked up my car to a rolling recapture/charge machine. .9lbs 134, but 150# on low side. Compressor not coming on. Hooked a scanner up to it, then 'reset' the control unit per a fax from the MB dealer. No dice. Strongly thinks its electrical-- pressure regulator relay (?), but worst case bad compressor. Going to take it to Richmond, MB Friday.....

[DieselAddict]

There should be some backflow-preventing mechanism somewhere in the hose kit. I've never seen any backflow even with an empty can.

[John Doe]

Originally Posted by DieselAddict

There should be some backflow-preventing mechanism somewhere in the hose kit. I've never seen any backflow even with an empty can.

Well, the can blew out like a balloon to the touch. The evacuation device looked pretty fancy and the reading on the gauge was 150#+. Should I send it to Ripley's?

[Matt L]

Is your EC lamp stuck on? If so, you'll have to reset the code before the compressor will activate. What code you have will give you an idea of what to check (if anything).

[John Doe]

Originally Posted by Matt L

Is your EC lamp stuck on? If so, you'll have to reset the code before the compressor will activate. What code you have will give you an idea of what to check (if anything).

The mechanic cleared the codes, and then scanned it--see post above. Its going to the spa today, and I will have to 'trust' them b/c I won't be back for a month