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2001 E320; 2002 ML500
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Discussion Starter #1
Hi,
So I have a 2001 W210 with AC problems (see other posts where symptoms and codes are described). After extensive troubleshooting, I'm fairly certain the evaporator is leaking.
I refilled the system with R134a with a dye and found traces of it coming from a hose in the bottom of the car about 4 inches above the transmission pan (see pics). There is no other trace of the dye anywhere else in the system.
So, this "evaporator" failure was supposed to happen to my 14 year old 223K mile W124 not to my newer W210, right? Guess again....
I've searched the forum and can't seem to find posts were troubleshooting evaporator leaks are described but I'm pretty sure it's the evaporator anyway...
Anyone have the procedures (pics would be of great help) on how to replace this dreaded device? Right now I feel like torching the car!
Thanks
 

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E320/E250 Bluetec Ford F350 6.7l
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Can't make much from the pictures, but that looks like drain tube?
Sorry to hear about troubles. My friend had AC compressor going kaput on 4 years old Volvo. The replacement would cost the car value. Depends how you look on it -it can be good, or bad thing.
 

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Discussion Starter #3
Thanks.
Yes, it looks like a drain hose/tube although I couldn't see were its connecting to.
Worst part is we had a '99 ML430 that my wife loved. I convinced her the W210 would be a better vehicle. She doesn't seem so convinced now...
 

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E320/E250 Bluetec Ford F350 6.7l
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He..he.. it was similar in our family. We gave our perfectly running ML320 to our son and bought ML55 that my wife couldn't use because of constant headaches.
Than I bought W210 4-Matic wagon and got swapped with $1200 CV joints replacement.
Our son is using the ML320 trouble free all those years.
 

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Outstanding Contributor - Always Remembered, RIP
Zotye Auto 1.5T T600 2016
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From the pics, I would have to agree that the problem is the evaporator. To change this means removing the whole dashboard and centre console. Do not attempt to do this job yourself unless you are a very competent DIY person.

If you feel competent enough then buy the CD copy of WIS first and read all the relevant AC sections.
 

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E-Class 300 TD 1998, E-Cllass 290 TDi 1996, 601 DKB 1982(207D)
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Sergio,

I can imagine that you have this feeling, albeit that prior to start this job (which is perfectly described in the link below, with lot of pic's), I would recommend you to at least have a second opinion from an AC-specialist.....
The reason for this will be clear in the DIY....it is quite a job and as Eric commented in previous reply...the dash needs to be removed indeed.
PeachPartsWiki: Replacing the A/C Evaporator Coil

The author of the DIY says: "I'd definitely recommend this project as a diy.", but read the text...see the pics...and judge for yourself. Its quite a W210 slaughter that needs to be done....

Cheers,
Ingmar


BTW.Moderrators....this link http://www.peachparts.com/Wikka/DoItYourSelf contains als a couple of other W210 DIY....perhaps a suggestion to include the in the top-sections of the forum ?
 

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E320/E250 Bluetec Ford F350 6.7l
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Kajtek1... how many Merc do you have in your family? Sounds like your whole family is using MERC
See my topic at http://www.benzworld.org/forums/general-mercedes-benz/1326590-do-i-need-mercedes-anonymous.html
Let's just say we had better times.
The only advice I can give Sergio is that with used vehicle what really counts is solid base and this is what you have in MB. Fixing cheaper, used car might bring you to the point that when you finally fix problem #10, the #1 is already failing apart. The issue is quite popular between RV owners. While lot of cheap RV go to junk yard having 10 years, those aircraft quality Airstrams are constantly restored and on the road after 40 or even 50 years.
 

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Sergio, there is a special tool available to test the evaporator. I suggest that you buy or make one.

To make one, plan to get a new TXV because you are about to destroy your old one. Remove the old TXV from the car, get appropriate pipe thread taps, and put threads in the front side (the side that does not connect to the evaporator). Into these threads, screw some connectors that end in 1/4M flare fittings, after you completely remove all the debris.

You can attach a gauge set (r12-size hoses, 1/4" SAE) to these fittings, fit the modified TXV with new o-rings to the evaporator lines (be sure to lubricate the o-rings with nylog or DEC PAG oil), charge with something (if there is NO refrigerant in the evaporator, because you blew it out, you can use air). Close the valves and monitor the pressure. If it drops, you have a leak.
 

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Discussion Starter #10
Thanks for all the replies. Why is it that the Japanese can build vehicles that last very long and are as reliable as anything on the road? My brother in law has a Honda Civic which he drives like he stole it. Performs scheduled maintenance at the dealer but never takes care of anything. He has well over 100K miles and told me he wanted a new car "when this one breaks, but no matter what I do, I can't break this thing."
The wagon already had both front shock absorbers replaced, ball joints, lower control arm bushings, CPS, rear wiper fluid hose came off, instrument cluster display with missing pixels, window regulators that break, sun visor mirror covers that break, shall I go on....
Right now I'm upset (I guess you can guess by the tone of my e-mail.
I'm looking into quality sealers. Cryo Seal is supposed to be the one to use; even MB dealers use it! I will give it a shot and if it doesn't work, I'll tackle the evap replacement myself.
Matt, the drain hose above the tranny pan is covered with dye. If it is not the evaporator, what else could it be in that area? Do you know the tool part number and cost?
Thanks!
 

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It just might be the connection to the evaporator at the TXV, but I wouldn't be money on it without checking. It probably is the evaporator.

I'll try to get a chance to look at the FSM for that tool number, but I would just make one.
 

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Discussion Starter #12
So today I pulled a vaccum using the low and high pressure ports and a set of R134a gauges. It held past 29 in/Hg for at least two hours. Does the "traditional" vaccum test that I performed NOT take the evaporator into account? Does it stop at the expansion valve (TVX)?
Thanks!
 

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E320/E250 Bluetec Ford F350 6.7l
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I only wish Sergio the test would be so simple. I have good experience with AC systems from the past and am still stumped with my present unpredictable leak on our W210.
It can hold the pressure for 6 months and than to dump it in the mater of hours, to hold it for another season.
The only explanation I can come with is that compressor seal is having microscopic imperfection that affect it at certain times, but this is wild guess only.
than as long as I can pass season with $10 of refrigerant addition, I can live with it.
Good luck on your problem
 

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Keep running it in winter for once every week as the user manual suggested may prolong the life of your AC system.
 

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So today I pulled a vaccum using the low and high pressure ports and a set of R134a gauges. It held past 29 in/Hg for at least two hours. Does the "traditional" vaccum test that I performed NOT take the evaporator into account? Does it stop at the expansion valve (TVX)?
Thanks!
This test doesn't tell you much for two reasons.

First is that a crack may be pulled together by a vacuum (actually pushed together by the atmosphere), whereas it may expand under pressure.

Second is that the gauge set is a really horrible vacuum gauge. I cannot tell the difference, at all, between .2mm and 25mm (absolute) on that sort of gauge (a micron gauge shows it clearly). At sea level, that's the difference between 29.9" and 28.9" gauge vacuum.
 
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