SWiseman

I have the bentley and want to recharge the 134a coolant in my system. There is a quick connect high side port but no low side port. Bently says all service is done through the High side port in the system. Last year I had an independant mechanic charge the system. They used the low pressure switch port located just in front of the driver under the hood at the rear of the engine compartment. They removed the switch and attached a short coolant hose with a fitting that would screw on to the threads of the port. When you remove the switch, there is a Schraeder valve in the port. I have been looking to make up or obtain the right fitting to attach to this low pressure port. Can anyone help with advice or a source for the fitting. I am looking to make up an attachment hose from this port to a can of 134a coolant. Also if I can charge through the high side port,without useing expensive commercial evacuation, recovery, charging machines, I would appreciate any direction here also. I have never used the high side port to charge a system.

tpierce

it won't go in. I don't know about the doing the thing with the low-side. All i can say is be carefull, there is a lot of pressure in the system, it can go boom.

gondar

When the system is at rest (not run overnight and a cool engine) the high and low pressures will have equalized bleeding past the expansion device (pretty fast if it is a orifice tube, more slowly if it is a TXV) and/or the compressor valves. I assume Audi uses a TXV because it is more expensive (joke) but I honestly have not looked. Then the entire system will be at whatever pressure the refrigerant chart indicates. Very close to one pound PSIG at room temp 70 degrees, abt 70 pounds for r134a. NOT RUNNING. You can verify ambient high side pressure with a gauge.
A can of 134a at the same temp will be at the same pressure, unless it is placed in a pan of warm water, in which case the gas would flow slowly through a hose to the cooler system, if somebody happened to have connected the two. NOT RUNNING.

As all caution, connecting a continer to the high side of a RUNNING system 250-350 psig will probably burst the container.

All technicians should wear good goggles if doing work near R-anything.

PaulW

The system requires 800 grams of refrigerant.....have it evacuated and then recharged.

It's $125 where I am.....and the guy can tell you how much was in there. He'll probably tell you in oz or lbs.

Yanivic

Hi Steve, I had the same problem with the A/C. All I did was remove the pin in the valve (LOW SIDE PORT) and then fit a standard one way valve (sold at any auto parts store).

I then bought this charging system (3 cans, hose with presure gauge) and recharged the system with engine A/C running on high. The system works great with no problems, done about 4 thousand miles with A/C on all the time and has no problems... I Hope it helps.
Vinay.