uh oh.....my sl500's(AC) leaking dye...... - PeachParts Mercedes-Benz Forum

a2aa · #1 09-01-2003, 03:41 PM

....from the hose that's connected to the evaporator that drains water ouside tha car. Sad day to find out. It is labor day isn't it? I'll be laboring all year long to fix this....unless and hopefully that it might be the expansion valve...

can anyone out there tell me where the darn expansion valve is on a r129 sl500 is? Is there a slight bit of chance that this is what's causing the leak besides the evaporator?

And I need a tissue to wipe my tears...

psfred · #2 09-01-2003, 04:26 PM

Expansion valve is beside the brake booster.

I always keep kleenex in the car.

Peter

joe p · #3 09-01-2003, 04:35 PM

The expansion valve is outside the case. However, the heater core o-rings will leak into the case and make the same green mess as the a/c dye. Is the car losing freon or coolant? The evaps will leak on 129 cars and the job is about the same as the 140 to do. Sctratch that, the 129's are easier 'cause you can drop the top and get some headroom but the bracing is more complex.

Joe

a2aa · #4 09-01-2003, 06:08 PM

yup...it's leaking freon...unfortunately. So it's safe to assume that it's the evap that's doing it.... i was going through denial when i saw florescent dye dripping out from below...sniff, sniff....sorry emotions are just too high ...sniff...

I was charging the system every 2 mos. The suction side was dropping from 35-40 to 20-ish in that span of time.

++so , what now???? bite the bullet?? OR DIY?? I can rebuild brakes, do tune ups, replace timing belts/chains...CAn I do this??

Which brand to get?? _ I know that I would need an exp vlave, rec/drier as well....and I almost forgot---- Lots of tissue

psfred · #5 09-01-2003, 09:48 PM

Plan on a long weekend, I think. Get new vac servos while you are at it, the last one is only one step from taking the evaporator out and you DON'T want to do this job twice in a year....

If you have any doubts about the heater core, change it too.

Peter

a2aa · #6 09-01-2003, 10:48 PM

Have you dealt with this procedure? If you have, what inspiring words and tips can you give us "plunging into this wild ride"?
Any "I should have done that" kinda thing that you recall?

-Did you flush your system out and disconnected the compressor? Change oil?
-Did you change the evaporator with an original design evap(copp/alum) or an all copper or all alum design to prevent leaks?
-how many beers do I have to buy for this project?

thanks in advanced

joe p · #7 09-02-2003, 08:16 AM

Ok, I'd advise a case for AFTER your done, prefably a decent beer, not some wannabe.

The job is long and involved but not that hard, just take your time, lay out your hardware by peice and replace the o-rings on the heater core outet pipes as well. (dont ask, just do it.

)

You can figure 2 days with hand tools and no experience. I'd recomend a ACM core if you looking aftermarket or OE is not. Replace the dryer and switches as well, if by chance its a 12 car this is a good time to convert it as well.

Joe

a2aa · #8 09-02-2003, 10:56 AM

peter,

.....this would really sound stupid...what's ACM core??

Thankyou for all the encouragement and advice.

I will call MBZ HQ and chat with customer service and see why is it that with all the complications and design flaws of this component that they haven't done anything to correct it. Letting a component prematurley fail and leak hazardous refrigerant into the cabin and not do anything about it is not what I call good business. Granted that the car is a 94, this component is inside the cabin, away from outside exposure. This 42k mile vehicle is a garage queen. I have 3 other MBZ that have higher milage than this SL, my 560sl has 110k miles with an intact A/C. No reason for this $99k original sticker price car to do this. This is pretty much PREMATURE INCIDENT COMPONENT FAILURE/DESIGN FLAW imho. Regards

WHEW... THAT FEALT GOOD....thanks for the support

psfred · #9 09-03-2003, 01:22 AM

The "new" evaporators appear to be a defective design. Hans does one a week most of the summer these days, they crack at the piping joints.

Only showed up recently, so MB may not have a fix yet. They are aluminum, but so is the one in the 72, at IT doesn't leak!

Peter

rjpeters98 · #10 09-03-2003, 04:04 PM

I just finished replacing the evaporator in my 94 SL500. Got the part from AutoPart Street (found them on the web). It is mfg by Visteon. Seems better then the orig Behr part because it uses copper tubing. This is a big job! Took me a couple of weeks part time to finish. I'll try to send a picture along with this post. By the way, in addition to taking out the dash area you also need to remove the stuff on the engine side of the firewall (wiper assy, blower motor etc,.) so you can get to the heater hoses and the expansion valve.

a2aa · #11 09-04-2003, 11:10 AM

Thankyou so very much for replying. I DO need some pictures and guidance from you rjpeters98 and please send more pics. What is the website or number did you get the non-behr evaporator again??? So, all is working well now???? I salute you for doing it. I'll do it as well. No luck in leaving the steering wheel assembly intact, huh? and lastly----what's the difference between tube/fine and plate/fin???? which one do we have???
regards

rjpeters98 · #12 09-04-2003, 11:10 PM

Here's another view from the drivers side. Don't know how helpful it will be. Sorry, but I didn't take many detail pictures. My evaporator is the "tube" type. Your's should be the same. The phone for Autopart Street is 1800/475-1227. They have a web page with prices (don't recall it offhand, but use a web search to find them). They were very helpful and....the price was right ($212). Thats about half the Behr price (best price for Behr I could find online was $464!). And again, the Visteon is copper tubing!! I just finished recharging the sys this past Mon and everything is working great....so far! I tried to remove the dash without removing the steering wheel, but could not get enough clearance, and I was afraid to force it over the wheel. As it turns out the wheel is very easy to remove. I surprised myself on this job that I didn't break any significant (just a couple of little plastic tabs). That's one reason it took me so long..... when I had a problem figuring out how to take something apart, I would stop for a while (hours or days!) and noodle it out.

a2aa · #13 09-05-2003, 11:54 AM

I'm so very thankful for your input. I did speak with bob over at Autopart street. Extremely HELPFUL guy. And @ $212 - totally irresistable. And basing from your current status, it's holding up well. I just attended our MBZ club board meeting last night and one of the guys suggested to me to make sure that it's not just the connections that are giving me trouble before I totally rip the dash apart...so, the plan is to confirm the leak then order the part. And they too agree on the aftermarket evap that is all copper tubing. Another thing,did you flush your system and replace the rcvr/dryr & eXp valve? One independent MBZ repair shop said that only if your compressor breaks and or seizes that you have to flush.
Regards

rjpeters98 · #14 09-05-2003, 05:13 PM

I did not need to flush the sys or change the expansion value, but I did change the receiver/drier. By the way, I was able to verify that my evap was bad by pulling the heaterblower and related stuff from the engine side of the firewall. Once the blower is out you can see one side of the evap. On mine I could see the dye on the bottom of the evap fins and even a little on the blower motor. The only mechanical connection you have on the evap is where it connects to the expansion value next to the brake booster on the engine side of the firewall. So, if that is leaking it should show up in the engine compartment. While not impossible, it would be very difficult for a leak there to get into the evap/heater case.

a2aa · #15 09-06-2003, 02:36 PM

got it. I promised my wife that I will finish the patio cover before even "touching" the car. But with the plethora of information from you, I'm ready for battle. I'm going to plan to change the heater core as well, almost 10 years of service- 2 locals already adviced me to do so. It's actually the last thing before the evap location is reached. I'll take lots of pics of ooops, ahhhhs and most of all, oohh sh*&^ 's...thanks for the help