My w124 evaporator removal thread

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,

[Cal Learner]

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.

[ps2cho]

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

[pifcat2]

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.

[platt-deutsch]

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..

[ps2cho]

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?

[platt-deutsch]

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

Originally Posted by platt-deutsch

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..

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!

[Matt L]

Originally Posted by platt-deutsch

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

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.

[ps2cho]

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.

[ps2cho]

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.

[ps2cho]

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?