My w124 evaporator removal thread
 

I am getting ready to order all my parts I need for the evap replacement on my 1987 260E w124. Car was converted to R134a by dealership some time ago...Date Markings on sticker are all rubbed off.
I will be doing it myself. :cool:
Want to keep it all consolidated like my transmission removal thread. Cleaner and easier this way...

First my Reasoning/Diagnosis:
A/C works, but leaks out after about 1-2 weeks. Took it to a local euro indy (worked on 124's before) who checked for leaks and could not find any. He put in some UV dye and when we pulled back the carpet on the passenger footwell and used the UV light there was dye present on the side of the heater box (looked old though he said, probably not his dye). Safe to say it is the evaporator that is the culprit?
Anywhere else I should check before tearing up the dash?


General Evap Removal Questions:
Got 5 questions as of right now...

1) Brand of Evaporator? ACM good?

I want to replace all of the vacuum pods....Sounds a good idea for futureproofing? I only ever want to do this once...

2) Any other pods not mentioned there? My '87 260E VIN is A5390xx so I would need the late footwell pod correct? Seems a higher VIN# than 289310...so just want to double check I got this right.

3) Any other items you guys recommend replacing?

4) What about testing procedures? Is it possible to test the system with everything apart to MAKE SURE the leak is resolved before I put it all back together?

5) Does the Blower Motor need to be removed? If so, what about replacing the regulator on it?


Projected costs:
~$500 for Evap and 6 pods.

Reference threads:
http://www.peachparts.com/shopforum/tech-help/226049-w124-124-290-evaporator-vacuum-pod-bulb-replacements.html?highlight=expansion+valve
http://www.peachparts.com/shopforum/diesel-discussion/35373-w124-climate-control-vacuum-pod-replacement.html?highlight=remove+dashboard
http://www.peachparts.com/shopforum/tech-help/176132-my-turn-evaporator-party.html

Your list looks pretty good. Definitely do a podectomy while it's apart.

Are you SURE that the leak is not around the expansion valve? It can sometimes leak into the passenger compartment and fool you.

Now would be the perfect time to reverse convert back to R12. Now that most of the cars that originally used the stuff are off the road, the price has come back to a point not terribly more expensive than R134a.

I think the ACM is what most folks prefer. If I recall correctly, it is not dissimilar metals as is the original.

Examine all around the heater core, especially the connections for any leaks. They are not bad about leaking, but if it is, now is the time to replace it.

Once you have the evaporator in place and connected BEFORE starting the replacement of everything else check for leaks. How you do that is determined by what you have to work with. At the very least, do a gross leak check by pulling a vacuum and seeing that holds that vacuum for at least about 10 or 15 minutes, overnight would be better.

If you have nitrogen, a little R22 and a sniffer, that would be better. Both of those are ways that you can leak check without running the system.

The blower motor does not need to be removed for this operation. Consider this a separate repair.

Do you have a factory service manual or CD? It is invaluable for this project. I prefer to pull the steering wheel which means following the FSM for disarming and storage instructions. There are those who have lowered the steering wheel all the way and managed this job without pulling the steering wheel, but that's not my preferred method.

When changing pods, proceed cautiously. A broken plastic lever or piece connected the pod presents some serious challenges to over come.

Don't get in a Flat Rate hurry on this job. Take your time and lay out subassemblies and associated parts and fasteners in the order that you take them off, then reverse the order when you go back together.

Keep us posted and best of luck,
Larry

good idea
 

im going to try

Thanks Larry,

Yep I have the FSM on the job. Any other 3rd party ones?

My dad actually managed to get hold of 12x12oz cans of R12 so I would love to switch back. I have a sniffer, but I took it to someone else because I just wanted a second confirmation that he couldn't sniff anything in the engine bay either....just to cover any mistakes myself.

Propane OK in place of Nitrogen? That's what I was using before.

The Indy used his sniffer around the expansion valve and said he couldn't get any signs from it. I thought about replacing it first, but if I can't sniff any leaks on it, should be OK?

Are you aware of the correct procedures for a reverse conversion? It will be well worth your while.

As far as the propane goes, I'm a purist. I personally would never introduce a flammable or any other foreign substance into an a/c system for ANY purpose.

It would be illegal to draw a vacuum as a gross leak check and then once it passes that, blow a little R22 in the system for leak checking reasons. The legal way to use R22 for leak checking is to pressurize with Nitrogen and then introduce a few ounces of R22. You can then blow the 22 into the atmosphere legally under those circumstances. The reason 22 is used is because it is highly detectable by a sniffer. Too bad it's illegal to just shoot some R22 in the system without the Nitrogen. The Nitrogen pressurizes everything to help with leak detection, but for your purposes, a pound or so of R22 would probably verify your evaporator as leak free. Too bad it's illegal.

You know alot of companies use propane instead of R134A anyway right? And that freon itself is a flamable gas also? Shouldnt make any difference but you should replace the dryer and the sensors on the drier since your system will be open to the air. Also be aware A/C compressor would probably love a new charge of oil before getting all charged up.

Neither 12 or 134 are considered flammables. I don't know where that could have come from. You must not be in the US, because to my knowledge Propane is NOT used as an OEM refrigerant in any US systems. I know some farmers that use it in their tractor a/c systems, but they didn't come from John Deere that way.

R/D replacement is part of a proper reverse conversion, or any conversion for that matter. The complete flushing of ALL oil from ALL components so that fresh R12 compatible oil is part of a proper reverse conversion as well.

I have NEVER had trouble reusing sensors that have been "open to the air." You have to transfer them quickly and not leave them around on the bench overnight, but there's no problem reusing them as long as they're in good shape. When I do considerable system work, I pull the old R/D with sensors attached and seal it. Then after everything else is in place I put in the R/D last and not until I'm ready to start the evacuation very soon after it's installation.

Thanks for the info for post-op checks. I'll make it work.

Should I replace the RD, but keep the sensors? Anybody explain why either of these would need to be replaced after being exposed? Last thing I'd want is other issues after the leak is resolved.

At least I am learning quick about the A/C system! Never done any work on them before as my wagon has worked since I bought it without any issues. *knocks on wood...*

The R/D should be replaced any time the system is opened for any length of time. If you have really good vacuum pump and a somewhat new R/D, you might get by with not replacing it. In the case of a refrigerant conversion it MUST be replaced because it has accumulated the wrong type oil.

A conversion involves flushing the oil out of ALL components, replacing the R/D and distributing the correct amount of oil throughout the system; couple ounces in the condensor, a couple in the evaporator, etc. After everything is sealed up and while the vacuum pump is running, turn the compressor about a dozen times by hand to make sure there is no liquid locked in the compressor.

I've never heard of replacing sensors as a preventive maintenance step. As soon as you open the system, pull the R/D with sensors attached and seal it in a plastic bag. Then put the sensors on the new R/D just before putting it in place as the last item to seal up. Start your evacuation as soon as the R/D is in place and sealed. This pulls moisture out of the system before it has time to start soaking in the R/D dessicate.

I understand. The RD is not an expensive item looks like ~$25 new so I will put that on my list.

I have a vac pump...So all that is needed is to let it run overnight and then turn the compressor by hand and that should be sufficient in regards to "flushing" the system?

Do you know which of the 6 vacuum pods are the ones that are accessible from the glovebox? I am thinking of trying to cut down the costs a little on the items that can be replaced in the future without much work.

There is one pod accesible with the glovebox out, but it wouldn't be easy. I believe that it is the defrost pod.

Also, the footwell pod is accessible with the radio and CCU removed (2 pods on the '86 through early '87).

I'm sorry I thought you knew what was involved in flushing the system. To do this, you break every connection and use a flushing solvent blowing it through each line, the evaporator and the condensor and blow it out THOROUGHLY with compressed air.

This flushing is necessary to remove all the oil that was used with the 134. Once everything is thoroughly flushed and the flushing solvent is THOROUGHLY removed, THEN you have an empty system so that the correct amount of oil can be put in the system.

BTW, flushing of the compressor is NEVER done with solvent. Invert the compressor and turn it by hand to get out as much oil as possible, then put an ounce or two mineral oil or a synthetic R12 compatible oil and turn again by hand to rinse that through. Once all oil is out of all components and lines, and your new evap is in place, connect everything, saving the R/D for last as described earlier.

This is alot of work to go through, I know, but to do this job right, you would even have to do it if you stay with 134, because you have no way of knowing how much oil is in the system.

I sure would want to convince myself of the leak location before diving in on an evaporator. Your leak rate is high, so the dye should be plainly visible wherever it is.

It sounds as if he's done about as thorough of a diagnosis as can be done without pulling the dash. It wouldn't hurt to pressurize with nitrogand a few ounces of R22 then check with a sniffer, but it is pretty well diagnosed.

Thanks for the info guys. I'll pull back the carpet next week and take some shots of the UV dye I can see on the corner of the heater box.

I would figure either way though it has to be leaking...If the expansion valve is not, where else does the dye come from?

The only thing he mentioned about the running of the A/C was that it was not as cold as it should have been. He said the low side was 50 (psi?) and the high side was 200 (psi?). He mentioned it could be a clogged expansion valve. Seeing as I will be getting a new one anyway that would resolve it, but any thoughts on other possible causes?

There was a very, very minor sign of residue on the compressor...Are there seals that can be replaced or is a new compressor needed?

My point was about the mechanic who thought it was old dye behind the carpet. You can clean it up and run the test again.

If it's old dye, how could it have gotten there?

Should his parts list include o-rings for the heater core manifold?


Seems like they should be replaced at the same time you've got it out of the car with access.


M

From an old leak that had already been repaired.

In rereading the thread, Hirnbeiss has a point. The main point is in his pointing out that this is a profuse leak. You need to use a sniffer to ensure that the leak is in the cabin.

When I used propane before and put my sniffer in the cabin, I got nothing from the vents which is really strange :confused:
I thought maybe it wasn't enough to be making it into the cabin. It did not smell either...That is why I used propane in the hopes I could actually smell it myself.
The sniffer was working though as it picked it up because it would beep by the fill port just after I took the can off. So the sniffer wasn't bad.

He evacuated the whole system at the shop. If I were to fill it again do I still need to put oil in the system or would it still be there?

You mean it currently has a vacuum on it? You should not leave a vacuum on a system, especially a known leaking system. You will suck in moisture and contamination. It's never a good plan to evacuate until you are ready to charge the system.

Maybe evacuate is the wrong word? He just took all the R134a back out that he filled with as it was going to leak out anyway.

Which of the vacuum pods should be the BARE minimum that are unable to be swapped unless the dash is removed?
124-800-00-75 = Defroster pod (dual chamber)
124-800-02-75 = Center vent pod (single chamber, twist-on)
124-800-03-75 = Diverter pod (single chamber, small, attaches w/3 clips)
124-800-04-75 = Recirculation / fresh air pod 1 (dual chamber)
124-800-11-75 = Recirculation / fresh air pod 2 (dual chamber)

Just trying to cut my costs down on this...$500 is pretty steep for me...
I know the footwell one is not high priority + can be done later.

The only one that you have even a chance of changing without removing the dash is the defrost. I personally wouldn't even DREAM of taking the dash off without replacing them ALL!

The entire set of pods used to cost $80 or so. That was before all the world financial events of the last couple of years, so the exchange rates may have messed with those prices pretty bad.

Footwell pod(s) and defrost pod are somewhat accessible with the dash in place, but as Larry said, best to do all while the dash is out. I believe that I bought the set for around $200 last month.

Yeh cheapest I've found them for all 6 is $270 :(
Any sources for cheaper? I can afford to buy them all, just "attempting" to cut my costs, but if you really think I should do them all, I will do them all.

You're the only one that can make this call, but this is a 15 hour job. And even if you are taking the dash apart WITHOUT replacing the evaporator, it's a 14.5 hour job. You might could get at the defroster pod without pulling the dash, but I've never tried it.

If you have lots of time on your hands such that you can take the risk, then that's a different situation.

FWIW, I have done both the ACM and the Reinz evaporators, and I like the Reinz best.

:-) neil

I have enough time and I need to compromise with the cost...
Let's give a worst case scenario -- All pods fail. Which (2) would be the most priority ones to keep you cool?
They all work right now, so if I just replace the most important ones I will be fine with that. I also think once I have done it once I could dramatically decrease the time involved to take it apart again.

Not ideal, but trying to do the best I can. I will buy the Reinz evap over ACM based on ke6dcj's suggestion. It also is cheaper than the ACM.

When I did a podectomy, the pods weren't very expensive, so I didn't consider it, but it seems like I remember that the diaphragms were available to repair your pods. Since your budget is limited, you might want to explore this possibility. I might be having wild dreams, but I think I remember someone talking about doing this.

It would be a way to save money since you have time on your hands.

Good luck,

At one time, George Murphy at Performance Analysis (I think that's his company) sold a kit for renewing some, but not all, of the vent pods. George is MBCA Technical Director, so you can find his contact info on the MBCA forum.

Thanks for the information guys. I'll do some research on it.

if you're opening up the AC system, there is a complete o-ring and seal kit at AutohauzAZ

If you can afford the downtime, after you've tested them open all the pods and examine the rubber bellows for fine cracks. Then order the replacements for what you need. I'm not sure if there are high use pods but those would be first on the replacement list.

After you've removed the dash, the next time is much faster if you've taken notes. I have a whole video I shot so I remember the details. ;)

I put a bottle of stop leak in my 2002 S600 and it worked! I didnt have to replace the evaporator..It was about 35.00 for a little 2 oz bottle..

Hmm I never thought about giving stop leak a try...I don't want to ruin anything else in the system due to the stop leak. Any thoughts on this?

Also, if I were to test this, do I need to add more r134a oil into the system? The indy shop pulled all the refridgerant out when he was working on it, so does that mean it also pulled out all the oil? Any way to test this?

They probly only let the gas out .. the oil stays in the system and the compressor.. Here is a link to a sealant for car a/c systems . http://www.duracool.com/Duracool/acsolutions.html

PLEASE prominently label your system as having stop leak inside!!!!!!

If you don't it is very possible that some day, someone like myself will unsuspectingly recover this stuff into their expensive recovery/recycle machine and destroy it.

I am very much a free market, small government kind of guy, but if I had the magic wand that would outlaw only one class of product, it would be air conditioner sealants. They destroy entire a/c systems and unsuspecting recovery/recycle machines.

For those of you who insist on using this JUNK, PLEASE label the system as a courtesy to the unsuspecting tech that might work on it someday. That poor guy is just trying to put food on the table and shoes on the baby like everyone else. Give him a break!

Yes the oil stays in the sytem, but you don't just "let the gas out." A recovery requires that a vacuum be generated. 20" is quite a vacuum. A compressed-air-powered vacuum pump can only do a bit better than that.

If there's a vacuum in the system, air will likely enter through any leaks and will enter when you connect service fittings(*).

* - Unless you have manual couplers, the kind with knobs that don't press the valve when attached. Then you can attach with the knobs unscrewed, hook up your vacuum pump and evacuate your manifold and hoses. Then screw down the knobs. You're better off simply not disconnecting the fittings while under vacuum.

When recovering a charge with a recovery machine, there is a graduated oil trap in the machine so that you can see how much oil is removed during the recovery. This is so that if you are recovering to do a repair and will recycle and replace the refrigerant in the system, you will know how much oil came out with the charge. That's so you know how much to put back in.

With my machine a recovery of a partial charge will usually bring along a couple of ounces of oil. In most cases when you are recovering, you have a partially empty system. That's why you're working on it. If you were to recover the charge from a full system, you would probably remove more than a couple of ounces of oil.

Depending upon the location of a leak, you will usually lose a couple of ounces of oil with a significant leak. Recharging a system without adding oil is not usually a very good plan.

To add to what Matt said about the vacuum drawn during a recovery, the automated recovery system actually removes the refrigerant and then waits for a period of time to see if the vacuum is lost to a certain point, if so, it turns on and draws vacuum for a little longer. The actual vacuum level and length of time is in the 609 test but it's been a long time since I took it. Since the machine does this for me, I don't have to remember these exact numbers.

I ordered the Center vent pod only as it is only $18...I will test the rest with the MityVac and take the associated risk assuming they are functioning and don't "appear" bad.
All parts incoming this week. I hope to start next weekend. Got all the FSM's printed and in my hand along with BoxfordBenz's thread.
As stated earlier, I will first remove the R/D and ziplock it with sensors attached so I don't need to replace both of them. I also think I am going to stick with r134a...Just need this replacement as simple and cheap as possible. I'm going to be moving house in 2 months, so that's all the time I got to get this resolved!

I think I'm all ready and most questions answered. Fingers crossed! Will post back soon when I have started the surgery.

Since you have the FSM pages printed, that's really all you'll need. Did you print the pages for airbag and steering wheel removal? Some people say it's easier to lower the steering wheel and leave it on, but it only takes a few extra minutes to get it completely out of the way. It's just that you have to follow the procedure to do it safely.

Since you're in a mild climate, maybe you can get by with the 134 as far as cooling performance goes, but beware that statistically, a converted 134 system only lasts 2 years before further repair is necessary. That might be why you're dealing with repairs today.

Good luck and keep us posted.

Why would r134a over r12 need repairs earlier? If that is the case I would rather do r12...

I've removed my wheel before, so I am familiar with the process so I will remove it for ease.

As I have said, statistically, an original 12 system converted to 134 requires attention in two years on the average.

As far as reasons for this I expect that it is due to several different things of which the person doing the conversion has control over some of them.

To begin with you will have a higher high side pressure. There are many variables that come into play, so some systems will have only a marginally higher high side, while others will just go out of sight. Added pressure puts added strain on most components of the system, mainly the compressor will suffer the most punishment, but fittings, hoses, condensor, expansion valve, r/d all experience added stress.

Another issue is lubrication. Many systems get thoroughly flushed and a new r/d for the process and the proper amount of PAG or POE lubricant put into the system. Sometimes systems don't get properly flushed in the process. Sometimes systems don't get at all flushed in the process. I've even seen people simply charge them with 134 with no other changes including oil. These systems will suffer much more of course.

Another variable is seals and o-rings. A less than thorough conversion leaves the original o-rings, not meant for 134 to be left in place to try to deal with the added pressure.

By doing a THOROUGH conversion, the odds of early problems can be tilted in favor of longer reliability, but statistically even THOROUGH conversions don't fare well in the long term.

The 124 is a masterpiece of a car IMHO, but the a/c and automatic climate control systems are clearly the achilles heel of these wonderful machines. If these a/c systems were overengineered to begin with then they would be better candidates for the use of 134. Reality is that these systems are marginal from the get go. That makes them poor candidates for conversion.

The most successful conversion I've ever done, and the only one left in my control that I have not reverse converted is my 88 Corvette. For some reason, the GM vehicles of the late eighties convert VERY well. They were well built systems to start with, maybe because they were anticipating 134 mandates and just built them for it from the start.

I converted my Corvette in about 1999 give or take. I would have to look at my log book to know exactly when. Since that time I experienced a condensor failure, and I don't know whether I can lay that off on the 134 or not, since the pressures on this one are quite low as conversions go. The condensor was leaking out in the area of the coils which also could mean that it was road debris that damaged it.

Among Corvette people, these are supposed to be poor performing a/c systems, but mine will pull vent temps down to 38 degrees within just a few miles after setting in the Texas Sun and heat soaking all day. Go figure.

Sorry that I digressed, but my point is that the 124 is just not a good candidate for 134 conversion. Since you're in a mild climate, maybe a thorough and proper conversion could work for you. Also given the radical environmental California laws, you might be stuck with it no matter what.

Good luck and keep us posted. I'm glad to hear that you are pulling the wheel. I personally think that's the best way to go on this job. It's enough of an ordeal without having that steering wheel in your way.

Thanks for the info...I think you definitely swayed me. And I may be moving to AZ this year too, so temperatures will be a little hotter.

I bought the 'Santech O-Ring kit'...will it work for r12? I assume it will because r134a seals are backward compatible with r12, but not vice versa, correct?

For the actual back-conversion, I think the main item to do is just the flush to get the old oil out seeing as I am replacing the R/D? There isn't anything else right?

That's correct, a THOROUGH flushing of everything not new, then the correct amount of mineral oil or synthetic replacement. The green o-rings will seal with any refrigerant, but I recommend coating them with zylog before installing them as opposed to refrigeration oil.

Flushing of the compressor should NOT be done with solvent, but with the oil you choose for your system.

Larry, my 124 was converted in 2001, and I wish now that I had resisted the temptation. How realistic is a re-conversion back to 12? I would not be doing the work myself. Are indies still willing/permitted to re-convert? How about availability of refrigerant? Interested in your thoughts.

EDIT: looks like you and I posted about the same time, so your latest response may address some of these points. Thanks.

Cal,

Unless your system has a problem of some sort or just won't keep you cool at all, I would not do the reverse conversion. Once the system has to be opened and repaired for some reason, then it would be a good step.

There are some states that have some crazy laws about a/c service, but I would expect that the Florida congress would have enough experience sweating that they wouldn't get too crazy about it. If that's the case, I believe that a shop could legally reverse convert an original R12 vehicle. The only thing that may come into it from a legality stand point is that they must RECOVER the existing refrigerant. That goes for either 12 or 134.

To do the conversion on a working system would require breaking of all connections, flushing all these broken apart components, flushing the compressor and replacing the r/d. It would be probably a half days work if nothing else went wrong.

Received my Reinz evaporator today...Looks good!

Funny question...Does it look like this thing came with the expansion valve? It said in the description it did, but it looks different than the ACM one...:confused:
Am I missing something here!?

ACM:
http://img.eautopartscatalog.com/hir...300&height=300

Reinz:
http://img.eautopartscatalog.com/hir...300&height=300

The top picture has an expansion valve, but I can't make out the bottom picture.