Next . . my turn to replace the evaporator - PeachParts Mercedes-Benz Forum

JimF · #1 08-02-2007, 05:16 PM

Well, my turn in the barrel has come to replace the dreaded leaking evap.

A few weeks ago, I replaced the drain hoses and found UV dye in and around the drain nipples.

I plan on replacing the compressor, drier, evap + Ex valve, all gaskets/seals and use a PAG oil . . w/o any UV oil.

My questions;
1) What vendor would you use to replace it?? ACM (all alum), Valeo (copper), and Behr (alum) or any others that you have used.

Any words of wisdom would be appreciated so I don't do what this guy just did .

brewtoo · #2 08-02-2007, 05:22 PM

Well, I guess you're sorry now that you replaced those hoses!

As you probably already know, I used the ACM evaporator.

It was a nice piece and it almost fit well.

Be careful, my first one was damaged in shipping as it had NO packing in the box, evidently from the factory.

JimF · #3 08-02-2007, 05:38 PM

Quote:

Originally Posted by brewtoo

Well, I guess you're sorry now that you replaced those hoses!

As you probably already know, I used the ACM evaporator.

It was a nice piece and it almost fit well.

Be careful, my first one was damaged in shipping as it had NO packing in the box, evidently from the factory.

As you may recall, I posted into your thread re drain hoses. I knew it was leaking b/c 4 yrs ago, I used leak sealer! Printed small so nobody would see!

Yes, I saw the dimple in the end tube. What you do mean it almost fit well?? Did you need a 'filler'??

brewtoo · #4 08-02-2007, 11:02 PM

The TXV area where it comes out of the box did not quite fit as well as the original. I put a bit of sealer around the big foam gasket.

Consequently, my TXV ended up sitting slightly forward compared to the original and I had to loosen the clamp that holds the low side hose in the engine compartment so I could move it forward a bit.

The original fit PERFECTLY, but the ACM was acceptable. Of course, the original leaked and the ACM doesn't. They may not all be exactly the same.

Matt L · #5 08-02-2007, 11:11 PM

Get DEC (Double End Cap) PAG oil for the system. It is not nearly as hydrophilic.

JimF · #6 08-02-2007, 11:15 PM

Quote:

Originally Posted by brewtoo

The TXV area where it comes out of the box did not quite fit as well as the original. I put a bit of sealer around the big foam gasket.

Consequently, my TXV ended up sitting slightly forward compared to the original and I had to loosen the clamp that holds the low side hose in the engine compartment so I could move it forward a bit.

The original fit PERFECTLY, but the ACM was acceptable. Of course, the original leaked and the ACM doesn't. They may not all be exactly the same.

What was the original??? Could you see the manufacturer?? A Behr??

brewtoo · #7 08-02-2007, 11:52 PM

I didn't see any names on the evaporator, but my guess would be Behr. You can buy the entire heater box from the stealer and I think Behr makes it.

JimF · #8 08-03-2007, 12:20 AM

brewtoo, got another general question; how long does your A/C take to 'pull-down' the temp? Have you ever measured it??

I saw your thermometer readout (actually looked like 37F air) but how long does it take to get there on a hot day??

brewtoo · #9 08-03-2007, 10:15 AM

Gosh, there are just so many variables. I have never really measured. I run the fan on low at first to get the components and ductwork cooled down and the air temp in the low 40s, then I change to auto.

One thing that made a big difference was getting all the crap out of the front fan shroud. Seems like the entire bottom third of the condenser was probably blocked. I was surprised at the improvement from that.

Pulling a really good vacuum on the system before charging, I believe, was a positive factor as well.

JimF · #10 08-03-2007, 10:33 AM

In the later model MBs, you can use the N22 control panel to readout the various parameters and 'watch' how well your ACs works. The details for my car are shown in MENU#15 under "Operational Checks". This procedure works for most MBs.

Press the "REST" button until the panel indicators change and display the key internal parameters. Two that show you well your AC is functioning is #5 (evap temperature) and #7 (compressor pressure in BAR).

For example, there was a '02 E430 at my tech's shop and I checked it out. From a cold start (80 deg day), The evap went from startup temp (70F) to 40F in 15 secs (cold engine). Then a few seconds later, it continued to go down to 33F and cycled between 35 to 39F even as the engine started to warm. That's my definition of a 'good' working AC!

I hope to get my AC to do this again.

david s poole · #11 08-03-2007, 11:05 AM

jim,based on experience i would use the behr.i have been caught many times trying to use an aftermarket only to lose lots of time when it would not fit exactly,usually around the xpansion valve.

JimF · #12 08-03-2007, 12:15 PM

Quote:

Originally Posted by Matt L

Get DEC (Double End Cap) PAG oil for the system. It is not nearly as hydrophilic.

Yes, I did . . . tnx for the suggestion.

Quote:

Originally Posted by david s poole

jim,based on experience i would use the behr.i have been caught many times trying to use an aftermarket only to lose lots of time when it would not fit exactly,usually around the xpansion valve.

Appreciate your input . . . what Txv do you recommend to use w/ the behr evap??