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Witek_M,
I think your idea is a very good one. I can make a hole in the bulkhead and cover that with a cap later, if needed. Now I have the drill and the Dremil kit with the cutoff wheels. Either way, I can see a path to success. I asked the dealership for the price of the two screws and they quoted me $10.01 each and also told me that they are out of stock !
And of course screws from MB have 3 mm allen heads. Avoid them.

Your biggest challenge is to be square with screw head and avoid contamination. Smallest debris from drilling will destroy compressor. Hold valve steady with clamp to avoid transmitting vibration to evaporator. Assistant is needed.

Take some pictures for future generations. :)
 

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E320 Yr 2000, S430 YR 2002
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535 Posts
Discussion Starter #62 (Edited)
I am trying to think through the reasons for the leak, since I used new O rings on both sides of the expansion valve. My thinking is that the clamp at the front that is held with the 10 mm Nut is responsible for holding the high and Low pressures lines from the compressor, so need to be adequately torqued. On the back of the valve the two hoses from the evaporator are probably held in place with the two bolts that go through the valve body, so these must also be torqued correctly to make sure nothing opens up under any pressure. Should I be using loctite blue at the two screws to make sure nothing comes loose ?

I tried to cut a nice slot into the screw but failed miserably. However, i did cut-off enough of the valve to be able to remove it with a Dremil and a cut-off wheel. A new valve will be here at the weekend as will the screws. Pictures of the cut-off valve are embarrassing,, so will not post -- its a hack job. The O rings were still present behind the expansion valve, so I can only guess that I did not torque the screws very well. I will try to use a torque wrench next time.
The old screw has a washer as well. Seems kind of small to be able to get it easily. Any suggestions ?

Anyway, the project is still alive.
 

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Discussion Starter #63
The old screws on the expansion valve have a washer. Seems kind of small to be able to get the washer easily. Any suggestions on parts that may work -- Witek_M has already identified the bolts that should be here by the weekend. ?
 

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Discussion Starter #64
The old screws on the expansion valve have a washer. Seems kind of small to be able to get the washer easily. Any suggestions on parts that may work -- Witek_M has already identified the bolts that should be here by the weekend. ?
I have the shiny new bolts and the 4 mm key.These bolts are slightly longer than the previous bolts -- perhaps 1/10 inch. I also bought OEM ( Mercedes Dealership) O-rings for the two at the back of the expansion valve. I used a cotton swab on the Evaporator lines and noticed that the high pressure line has some black residue. I am planning to flush the evaporator, but I do not have compressed air. I do have a compressor for tires. Do I have to buy a compressor to use the flush solvent or can I rent one or use the one for the tires ?
 

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Tire inflator does not have enough volume. Rent compressor with tank.

When installing new EV put o-rings on evaporator using fingers only. Plastic gun cleaning pick is OK.

 

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Discussion Starter #66
Matt and Witek_M,
I have flushed out the evaporator and reinstalled the EV. Should I add some more refrigerant and die to test for a leak, or should I get the manifold gauges and vacuum pump to see if it now holds vacuum or at least know ifthere is currently no refrigerant in the system ?
 

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Matt and Witek_M,
I have flushed out the evaporator and reinstalled the EV. Should I add some more refrigerant and die to test for a leak, or should I get the manifold gauges and vacuum pump to see if it now holds vacuum or at least know ifthere is currently no refrigerant in the system ?
You've had that system open for over a week. It is full of moisture. Evacuate for at least two hours. Put can in dish with hot water. Charge with one can, close all the valves and start looking for leaks. Any joint you had apart. Teaspoon of dish washing liquid into quart of water and spray bottle.

Before starting engine rotate compressor hub by hand few revolutions.
 

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Discussion Starter #68
Please take a look at the picture: The bottom tube has quite a bot of play in it in the horizontal direction. while the top is pretty solid. When I install the two screws the whole valve body has a play in the horizontal direction despite being torqued. Is this normal or an issue ?
2623124
 

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Lower tube (inlet) goes across front of evaporator to right side. It is normal for it to have some flex. Evaporator is mounted inside the box with foam blocks. It is not solid. There will be some movement.

Search 210 830 10 58 for more images.


2020-03-08_162553.png
 

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Discussion Starter #70
Witek_M and Matt,
I have success !.

Took out the expansion valve and replaced it again. I used two O-rings from the Santec kit I bought,( rather than the MB ones) at the back of the EV. I charged with with a can and half of R134A. Compressor engaged, diagnostic show pressure at "07", Its a cold evening here in San Jose, so a good test would be on a hot day. I am not sure that I should re-evacuate the system and recharge after vacuuming again next weekend. I think that is probably the only way to make sure I have the exact amount of R134A,. At that stage, should I also add more PAG 46, or will the amount added in the system at the time I changed the compressor will still be there ?

I was very close to giving up and taking it to the shop, but great and timely advice from both of you helped me a lot, on my first A/C project.
 

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1998 E320 base sedan @ 160kmiles
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In my opinion you should evacuate and and vacuum to ensure that the moisture in the system is minimized, and you can put the precise amount (3 * 12 ounce cans considering the few ounces of loss left in the cans, and hoses. Make sure you purge the air in the hoses prior to refill (just let some gas fill the charge hose prior to tightening the charge port). The Denso compressor is supposed to have the PAG oil required. Do not put extra oil, as it will reduce the cooling capacity. You can always add later on, if needed.
 

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Discussion Starter #72
Matt, its a good job I followed your advice. When i took it to the shop, he said there is still a problem with the Expansion valve still ! He told me that there is a guide pin on the EV or on the car side that may not be fully aligned. However, I do not remember seeing any guide pins. I need to look closer.
The guys was nice and told me that he would have to charge around $300 for the EV and told me me to do it myself. He said that the O-ring at the engine side is sticking out -- i.e. the green O-ring can be seen, but need to be pushed in further.
I may have to go to Pick n pull to see how the connected EV looks like, since I did not take any pictures when I started the project.

When I had a little bit of R134A in it, I saw that the number 7, value on the diagnostics went between 5 and 8, so I thought I had a seal and just needed more refrigerant.
 

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1998 E320 base sedan @ 160kmiles
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He is probably talking about the stud from the EV to the hold-down piece to hold and press the pipes. You need to remove the 10 mm nut, remove the hold-down piece and re-align the pipes (after replacing the o-rings). May be one of the pipes is not held straight -in.
Removing A/C Expansion Valve on W210
 

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Discussion Starter #74
I see in these pictures that once the pipes are assembled in the EV, the O-ring cannot be seen, unlike in mine where I can see the O-ring between the EV and the pipe, after installing the 10 mm nut. I will try pushing in the pipes again harder into the EV and see if I can get a better seal. I thought that perhaps the Santec O-ring was thicker than the OEM, so it does not go all the way in.
 

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Both of the pipes should go into EV without any effort other then alignment. Do not use 10 mm nut to drive them in.
 

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Discussion Starter #77 (Edited)
Matt and Witek_M, I have bought another expansion valve made by 4 Seasons. model is TBF 2D No 324304.
This came with O-rings.
However it has 5 Orings and I am not sure where they go, since there are only 4 inlet/outlets.
Please see the picture attached.

2624427


Only the high pressure side( narrower tube) that connects to the evaporator seems capable of accomodating two orings. One small one that may go deep into that hole and one larger one thats near the top of the hole in the valve.
 
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