As of today, the AC seems working OK after cleaning the duovalve and adding 16 oz of R134a. Thanks to Wood’sbenz. Following are the pictures I captured while working on the duovalve cleaning job. I strong recommend to use a rag or paper towel to block the cavities around the duovalve so screw or other parts don't drop into it. Trust me, you don’t want to drop anything in there.
Thank you Wood'sbenz for the detail steps on cleaning the duovalve and thank you netdvn for posting excellent pictures. I have an E420 1997 and I am experiencing the same problem with my air conditioner too. However, when I turn on my a/c it works for a few minutes and then starts to blow warm air, not hot air. I don't have a computer so I can't retrieve the codes to share with you fellas. I do want to try and fix this myself because I have donated too much money already for other unexpected repairs. I need your help with the following questions before I proceed:
1. Where can I buy some R134a refrigerant?
2. Please provide detail instructions on how to fill the a/c system with refridgerant.
3. Any other suggestions would be greatly appreciated.
You can buy R134a at any auto parts store, Wal-Mart, etc...any place with an automotive section will have it. You'll need to buy a can that also has the gauge/hose/fitting attachment too. Fill the AC at the low pressure port. This is located on the driver's side of the engine compartment about midway back and to the outside of the engine. There should be a black dust cap on it and the lines will most likely be aluminum. Remove the dust cap, snap the R134a fitting over it (make sure it is snug), start the car and turn the AC on cold. With car running , release trigger to fill AC system with refrigerant. Watch the gauge, making sure not to overfill if possible. If you're very low, I'd suggest buying a larger can - they usually come in multiple sizes.
Last edited by wood'sbenz : 06-19-2006 at 02:36 PM.
Alright fellas, these are great instructions in this thread. I will run out to Walmart and pick up the supplies. Then I will try and perform these steps that you guys provided and report back and let you know the results.
Thanks again! -SF E420
Oh btw, is there away to tell how much R134a are in the vheicle's a/c system?
Oh btw, is there away to tell how much R134a are in the vheicle's a/c system?
Buy a can of R134a that has the gauge/hose/fitting attachment. The instruction on the can will tell you how to use the gauge. Make sure shake the can well before and during refilling.
Oh btw, is there away to tell how much R134a are in the vheicle's a/c system?
There is no way to tell the actual volume of refrigerant in the system unless you go to a shop with an evacuation machine that will remove the refrigerant and measure the amount. You can run a diagnostic via your electronic climate control to see how many bars of pressure you have within the system, but with our variable pressure compressors, this will do you little good but to give an initial point of reference after adding additional refrigerant. Once you attach the refrigerant fitting, the gauge will show the pre-compressed pressure in the system. The gauge has color keyed areas for low, normal and high range within the system. The system has a high pressure limit protection feature, so you won't damage the compressor in the extremely unlikely event that you over-pressurize.
Last edited by wood'sbenz : 06-22-2006 at 02:44 PM.
thanks a lot wood'sbenz, i thought i was a little low on r134a so i bought some and went to put it in and the gauge registered full, or blue, correct level, so i figured i needed to clean the duovalve, i took it off and cleaned it out and lubed it, but couldn't get it back on without removing the plug, so i tried to remove the plug and broke two of the little copper wires connecting the coils to the plug!! it looks like someone with very small, steady hands and a little electrical knowledge could fix it, but i will probably have to spring for a new one, $175! My own stupid fault!!
... broke two of the little copper wires connecting the coils to the plug!! it looks like someone with very small, steady hands and a little electrical knowledge could fix it ...
i have a 98 turbodiesel with the same problem. i assume that i can fix it the same way that you have but do you think there are any differences between the two a/c systems that may need to be addressed?
How do you get those codes from the A/C. If I understand, you can read then on the A/C control head. What is the secret botton combo to get them to come up?
Thanks,
Frank
__________________
If you are not living on the edge, you are taking up too much space!
-SF E420
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