Next . . my turn to replace the evaporator - Page 2 - PeachParts Mercedes-Benz Forum

david s poole · #16 08-04-2007, 10:38 AM

any tx valve will do.look at last pic--the valve will fit on coil BUT are the pipes at the correct angle so that you can easily close the case and put on the clips without struggling?that has been my bone of contention with the aftermarket units.they fit in case but closing it afterwards leaves a lot to be desired.

JimF · #17 08-04-2007, 11:19 AM

David, your answer prompts this question . . . if the angle/connections are not correct, do your 'bend' the extension tubing until things 'mate' or close??

Is that an acceptable procedure that won't put pressure on fittings and joints in the evap??

brewtoo · #18 08-04-2007, 06:23 PM

Quote:

Originally Posted by david s poole

any tx valve will do.look at last pic--the valve will fit on coil BUT are the pipes at the correct angle so that you can easily close the case and put on the clips without struggling?that has been my bone of contention with the aftermarket units.they fit in case but closing it afterwards leaves a lot to be desired.

Yes, that's the problem I had, too.

david s poole · #19 08-05-2007, 03:34 PM

i would be very hesitant about applying much force to aluminum pipes only to find out when assembled that i created a leak.

JimF · #20 08-05-2007, 05:27 PM

Quote:

Originally Posted by david s poole

. . . . BUT are the pipes at the correct angle so that you can easily close the case and put on the clips without struggling?that has been my bone of contention with the aftermarket units.they fit in case but closing it afterwards leaves a lot to be desired.

Quote:

Originally Posted by david s poole

i would be very hesitant about applying much force to aluminum pipes only to find out when assembled that i created a leak.

So what, specifically, do you do to get them to fit?

david s poole · #21 08-05-2007, 09:26 PM

if you use oem coil it will fit without bending unless damaged.

JimF · #22 08-10-2007, 09:38 PM

I have two (2) evaps; ACM and BEHR. Both look identical in size and position of the Txv, so either should work. . .

But the BEHR has copper/alum . . WTF! Why would they still have both metals?? I couldn't believe my eyes. . for sure the ACM is going in!

Removed the drier and comressor . . the drier was loaded with UV-oil (as it's supposed to be).

But the 'bust' of the day was the condenser. I ordered a new one b/c I figured I'm replacing everything else so why not the condenser.

Got the old one out . . comes out w/o removing the radiator, so it was fairly easy. The replacement was identical . . . so I thought. . . . but when I removed the fan assy (got a chance to clean and lube) and mounted on the new condenser, I discovered that it WASN'T identical.

BION, these new ones have a long radius on the bottom "pipe" fitting such that it won't clear the front edge of the radiator and thus won't properly fit nto the bottom mounts.

I wasn't too happy . . .

. . at that point b/c of a lot of wasted time. Had to clean and flush the old condenser. Did so and removed a lot of UV-colored-oil. Seemed to come clean . . so it's the one that HAS to be used.

Tomorrow the evaporator. . . and probably the next day . .

brewtoo · #23 08-10-2007, 10:38 PM

...and probably the next day...

emerydc8 · #24 08-11-2007, 07:13 AM

Maybe I missed something in the above string, but I'm wondering if the UV oil causes any clogging or affects the efficiency of the a/c? It sounds like the UV oil collects in the r/d. Is that a normal place for the compressor oil to collect too, or is the UV oil a bad thing for the a/c system?

I'm asking because I just used some UV dye to find a few leaks in a Chevrolet. It does show up very well at night with a black light, but now I'm wondering if its going to clog something. After I found the leaks, I pulled the system down to 26" hg (all my Harbor Freight vacuum could do) and recharged, but I suspect the UV oil stays until flushed. Is that a correct assumption?

Good luck on the job, Jim. I hate when I get the wrong parts. Interesting about the two metals, though.

JimF · #25 08-11-2007, 09:25 AM

If UV-oil does, I'm not aware of it. What I was trying to get across, is the fact that there was too much 'oil' in the AC system and there's nothing 'bad' about the "UV" part. It just happens that most use a UV-oil as the 'normal' oil.

Too much oil (whether UV or not) will reduce the AC's efficiency.

I will take some pics and show what happens. . .

david s poole · #26 08-11-2007, 10:37 AM

jim,now that condenser is out do yourself a favour and clean the paint off of it.that way it will be much more efficient.by the way check the behr coil.the old ones that leaked used epoxy to join the copper to aluminum-----the new ones are welded.it was the epoxy failing that caused the problems not the diff metals.when you pull out old one you will see what i'm saying.

emerydc8 · #27 08-11-2007, 06:36 PM

Does anyone know how long Mercedes installed these poor-quality evaporators? (up to what year). I'm not looking forward to replacing one. It sounds like max-no-fun.

JimF · #28 08-11-2007, 10:30 PM

DONE!

It was apart and back together in 10 hours . . . BION! Pretty good job for an old guy . .

The truth is I helped alot but had a master-tech do the work . . amazing, talented man. We had "zero" problems . . nothing broke, everything fit perfectly . . . and 'we' didn't break anything. We worked as a team . . and a very successful one at that. . amazing.

The ACM evap was the exact replacement for the leaking Behr. So it fit perfectly w/o any problems; the case closed w/o any problems.

Not sure what the vintage of the old Behr evap (at least 13 yrs old) was but it didn't leak from the 'amalgam' of cu/alum. It leaked at the alum 'weld', so I learned something. The new Behr evap was identical in construction but I decided, maybe incorrectly, to use the ACM.

Job was stated at 7:00a and all finished by 4:45pm; Pump down for 30 mins; leak test . .15 mins; charge and I was home at 6:00pm. Work was done at my tech's shop . . so we had all the tools necessary.

I forgot my camera. . so I used my cellphone but it didn't take very good pics. But you get the idea.

The A/C blows 37F air so I'm happy again. It cycles from 37 to 42F and the compressor cycles off for 10 - 15 secs before kicking in. All in all it's working as it should.

When we flushed the hoses (after the evap was out), there was sooooooo much oil even in the hoses. . . can't believe there was that much.

emerydc8 · #29 08-12-2007, 01:01 AM

Looks like they built the car around the evaporator! It doesn't look like fun. Congratulations and thanks for the pics. Now I know I never want to do this job.

JimF · #30 08-12-2007, 09:34 AM

it's some tough job b/c there's so many screws, clips, etc. Glad it's done.

Interesting that the site window on the drier shows the refrigerant as I remember it . . . a clear flowing mixture with some bubbles.

Before all I could see is a chartruese colored "mess" that didn't seem to "flow".