Dreaded W124 evaporator leak (its my turn!) - PeachParts Mercedes-Benz Forum

James L · #1 06-18-2008, 12:25 PM

1993 300D 2.5. After compressor replacement (bad air gap and clutch bearing caused kilma cut off), after evacuation, had small vacuum leak. Filled with R134A and dye. After a few days I have the dye in the water condensation in the driveway.

What causes these dreaded W124 evaporator failures? bad welds? aluminum instead of copper? copper/alum blends?

Anyway, I see there are 3 brands of evaporators available; ACM (all alum-$231), Meistersatz (all alum - $141) and Proliance (all copper- $126). Any opinions on these brands?

I dread the dash removal. Would like to not fix and just keep adding R134A and Pag 46 oil charge as needed.

dpetryk · #2 06-18-2008, 02:27 PM

Go all copper. They don't rot like the aluminum types.

JimFreeh · #3 06-18-2008, 07:19 PM

Quote:

Originally Posted by dpetryk

Go all copper. They don't rot like the aluminum types.

It's not the aluminum ones. The OE evaps are copper/aluminum.

I used an ACM on my trusted parts guy's recommendation.
So far, so good, it's been close to a year.

Not a bad job, just tedious. Took me about a week and a half, including two weekends.

About the same amount of time for both the W124 and the W126.

Jim

lee polowczuk · #4 06-18-2008, 07:22 PM

well... i am putting in a can every three weeks on my 260e...

it didnt' use to be that bad. i think when i drove less it didn't leaks as much

not doing an evaporator on a car with nearly 220k.

i can spend 7 dollars every three weeks on a can

Richard Eldridge · #5 06-18-2008, 07:58 PM

When mine leaked, I told the guy to put in a copper evaporator. He said he would, asnd then called me to tell me that the copper evaporator would not fit. So he put the %$#^! aluminum one in. Or said he did. I don't know what he did, but it continued to leak slightly ever after. $2100 I paid, and the damn thing worked for about a year.

I do not believe that there ever was a copper evaporator. I am not sure that any evaporator was changed. I went back once, he recharged it, and that lasted about 3 months. After that I have not darkened his door.

Curiously, the place is named Mercedeshop, no relation to this Forum whatever, in North Miami Beach. Go there and admire Gunter's fine German accent.

But don't have him fix anything expensive.

compress ignite · #6 06-19-2008, 01:26 AM

The O.E. installed at the factory had no protective coating on the Aluminum
core...AND rotted from the outside inwards.

(Some one will be along momentarily, if I'm wrong, to correct me.)

Screw the Aluminum...If you can get your hands on a Copper EVAP jump on it!

You'll only have to replace it once in a lifetime,then.

Jimmy,

Since you're doing the EVAP ...1.pressure test the Heater Core before you close
up that dash! 2.Replace ALL the air control vacuum operated pods while you're
in there(You will not be sorry)3.Might as well put in a Parallel Condenser and
improve the heat transfer rate by 30%.

James L · #7 06-19-2008, 09:24 AM

Thanks for all the replys! Keep em comming!

Phil has the "all copper" Proliance evap on this site ($126).

My worry with not fixing and just adding R134A as needed is that the Pag oil is leaking along with the refrigerant. This makes it hard to keep the correct amount of oil in the system. Could keep "winging it" with the R134A/Pag 46 oil charge.

Compress ignite, how do you "pressure test" the heater core? Yes, I will change the vacuum pods if I end up doing the dash removal.

Thanks

dpetryk · #8 06-19-2008, 10:46 AM

I was not clear in my earlier post. There are two types. One has copper tubes and the other has aluminum tubes. They both have aluminum fins. The ones with the copper tubes will not rot out as copper is less reactive than aluminum. It is the tubes that are the issue since the inner walls of the tube are where the chemical reactions are causing pin holes and leaks

tankowner · #9 06-19-2008, 10:53 AM

The PO of my car had the evaporator replaced and I have documentation of that. However, the receipt of that work only shows charges for the evaporator and recharging and leak testing the system. My questions is, shouldn't the receiver-dryer be changed out when the evaporator is replaced? What do you all think, should I be changing the receiver-dryer out for the sake of my compressor?

dpetryk · #10 06-19-2008, 11:08 AM

Absolutely the dryer should be changed.

James L · #11 06-19-2008, 11:12 AM

tankowner, if the system was open for along time, I might have replaced the rec/dryer. Proper evacuation (vacuum pump) helps with some of the air/moisture removal.

Someone asked me for the Proliance phone number; 800-755-2160, the website is www.transpro.com/. A photo of the Proliance evap is on the fastlane parts menu. Would it fit ok?

Richard, to see if "Gunter" did what he said; you can see some of the evaporator if you take out the monowiper and blower motor/case.

compress ignite · #12 06-23-2008, 12:49 AM

If Phil sells it to you it'll fit.

I'd pressure test the Whole Cooling System...You've seen the bicycle Pump
apparatus with a Radiator Cap Adapter? I believe the expansion tank cap
(which is our "radiator cap") is rated for 1.4 bar. [1 bar is one atmospheric
pressure or 14.7 PSI.] so the system is rated for at least 20.5 PSI ?

Not to lay all this on you at once...
GSXR has a rule,that if he doesn't know the age of coolant system hoses on
an older model...They All Go.

I'm planning to replace them all before the crank turns again.(18 years old)
'cheap insurance and peace of mind.

sixto · #13 06-23-2008, 01:43 AM

GSXR also has a 5 year rule on 124 radiators.

Sixto
87 300D

James L · #14 06-23-2008, 11:37 AM

Good call on all the coolant hoses, radiator. Already thinking about the ones going to the heater core thru firewall.

2 12oz cans of R134A has about all leaked out (2 weeks), so the evap pinhole must be big or numerous.

I am still debating doing this dash removal job since this car is old, has 211K and has other issues; peeling clear coat, sagging headliner, boost control issues, front driver side suspension issues, ect.