My 1990 300D 2.5 Turbo has a small leak in the AC. It seems to be located under the dashboard, an unholy place to work on. Therefore, I was happy to find that someone makes a sealer, Cryo-Chem International (www.ssrintl.com) called Cryo-seal, which they seem to sell only to EPA certified shops in kits of a half dozen or more.

I would like to know whether anyone has any experience with this product, or if there is an alternative similar product that might solve my problem. It gets too darn hot in Miami in the summer and I will be forced to drive (oh, the shame!) my rather reliable 89 Hyundai Excel, which has a cold AC.

Hi Richard, I have used that product and really hoped it would work as described.
It sorta did.I offered it to my customers on a test basis. as the maker warranted that if it did not seal , they would refund the cost of the kit.So I tried it maybe 10 times.
On 2 124 cars we put a new evap in after the sealer failed to stop the leak.Similiar results on 85 123 cars. (it seems that 85 123's used a junk core too. they all leak) On a BMW it worked permanently. On other 124's I have had problems with compressors leaking after wards, drier switches failing repeatedly, exp valves leaking.I no longer off to use the SSR cryo chem product.
The stuff is very hard on the equipment used to install it ,too. If it gets into the shops recovery machine they will hate you!
On 124's the evaporator is a common failure, and very pricey to replace.The dash comes out, HVAC box is totally disassembled, etc.
I also replace all the vacuum elements while the unit is apart.
If you intend to keep the car ,I would bite the bullet and replace the core. I did on my wifes car, and nobody hates to spend money on a car more than me. But, when you gotta do it....

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Michael Haven CMAT,CMM,L1
MPH Automotive Services
16510 Park Row
Houston, Texas, 77084
281-579-8885

Any experience with the sealer for $3.99 or $5.99 at Pepboys for a R12 system whereby you release the plastic tubed chemical with a ratchet wrench into the low side valvewithout the car running?
Fix or lease a new cheaper ML 320,that is the question?

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Tom 1992 300E 2.6

If you use this in your A/C, don't bring it to my shop to be worked on when it cooks the compressor and cloggs all of the lines. I took apart a 124 that had this done and it had to have every tranfer hose and part replaced. BIG $$$$$. Compressor, drier, expansion valve, hoses, evaporator, and condensor....BEWARE!!!!!

BEWARE BEWARE BEWARE BEWARE BEWARE BEWARE

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Benzmac:
Donnie Drummonds
1981 280GE SWB
1987 16V
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM

Even if you found an efficient, non destructive sealer, you would at best only effect a temporary fix. If the evap is leaking, that's gotta be replaced. If it's in the lines to or from, that might be easier, but, only slightly less expensive. Most of the cost of this job is labor. This is one area where the engineering kinda fell on it's face. This part should be much more accessible than it is. Especially since it is known to be a high failure rate item. I wouldn't go with the sealer (read Benzmac's reply 15 or 20 times).

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Jeff L
1987 300e
1989 300e
1987 BMW 325

[This message has been edited by jeffsr (edited 04-07-2000).]

I spoke with the Cryoseal people, who told me that they didn't know of any cars that this would not fix, and that a slow leak was the kind most likely to work. Of course, I imagine that every leak is somewhat different.

I have fixed radiators for as long as 10 years with good ol'Barr's Stop-Leak, which I will admit is a different product in a different place. After 10 years from the first use in a 77 Celica, I popped in another bottle of this marvelous stuff and it worked again. It never overheated.

On the other hand, I respect your opinion. But I don't really think I should have to lay out over $1,000 just to be cool in the summer.

Another concern is that having someone messing around under the dash could be an invitation to trouble. At the factory, these things are lots easier to work on. A wire could get shorted out and the results could be disasterous. I had this happen when I had some supposed experts working on a Buick not too long ago.

I suppose I need to ask around and find someone who really believes in this stuff before I give it a try.

Will the Cryo-Seal people warrant against any damage that their product produces. I'll bet not. Why would they bad mouth something they are trying to sell you. That's a basically poor business practice. If you try to visualize the inside of an A/C system, get a mental picture of expansion valves with tiny orifices, reed valves in a compressor, the small passages in the evaporator, capillary tubes and the like. I'm a cheapskate when it comes to finding the least expensive way out of a problem, but guess what, if this stuff really worked as advertised, then all the HVAC shops would go out of business. Find the leak and fix it right. This may be costly or it may not, depending, but why play Russian Roulette with some rather expensive hardware.

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Jeff L
1987 300e
1989 300e
1987 BMW 325

[This message has been edited by jeffsr (edited 04-08-2000).]

[This message has been edited by jeffsr (edited 04-08-2000).]

No, you should not have to lay out over a $1000. And yes, you expect your Mercedes air conditioning system to be as reliable and function as well as a Toyota Corolla or Hyundai Excel.

But the reality of the matter is if you have a W124 vehicle with the original factory all-aluminum evaporator and you live in the deep South, you have a problem. And if you fix it improperly at first, it will come back to haunt you. The system's components are intolerant of abuse. If you want reliable air conditioning at the lowest cost, you either do it properly now or do it properly later.

Heres the lowdown -

* M-B's all-aluminum evaporators, used in W124, W140 and R129 series vehicles, superceeded the indefatigable copper tube/aluminum fin evaporators used by the prior generation vehicles - W123, W126 & 107. Unfortunately, the all-aluminum units had an Achilles tendon - under the right conditions (aka, routine use?) the units starting leaking like sieves. The problem was prevalant in (and perhaps facilitated by) climates with high ambient temperatures and humidities. These aluminum evaporators were manufactured by Behr (in Kentucky?) and contained no external anti-oxidation/anti-corrosion coating. And leaks started developing. From the outside in. Tube wall integrity loss has been attributed to poor quality materials.... design defects.... corrosion... phase of the moon.... bacteria ... mites. I've spoken with many service techs, parts and M-B field reps (in the U.S., U.K. and Germany) over the years and received many different explainations. But one thing was consistent: at the service and parts level there was always the acknowledgement that a problem existed; at the management level, the opposite: "We do not have a problem with our evaporators" and
"Evaporators can not be expected to last more than 80-100K miles". But the most important finding was that the leaks invariably developed from the outside inwards.

* The W124 refrigerant compressors have no oil sump; lubricating oil is circulated throughout the system. Spring a leak? ... you can loose both freon and oil simultaneously. System not cooling well? Recharge with freon! But did you also replace the lost oil? One accompanies the other. The compressor's pistons are coated with teflon, which, in conjunction with the oil, prevents seizure. When the system runs low on oil, the teflon is abraded off and the pistons seize in their bores. The compressor self-destructs and sends metal particles throughout the system. Then you have to replace everything. Flushing can't effectively remove all the metal particles.

* Can the sealer truly prevent new leaks from developing? Particularly when they originate from the outside in? If the evaporator is leaking, replacement is the only remedy. Especially if the leaks are parasitic in origin.

Haven and Benzmac are right regarding the detrimental effects of the sealer on system components. Go to your A/C repair facility; ask to see a disassembled Nippondenso compressor. Note the internal clearances. A factory rebuilt, without clutch, is $500, plus labor. Is it worth the risk?


My service recommendation, from someone who has been there (more than once):

1) If you haven't done so already, thoroughly leak test the entire system. Now. While everything is still functioning. In particular, look for leaks at the evaporator, expansion valve, freon pressure switch located at receiver drier, and suction manifold hose assembly (bolts to compressor).

2) Check system pressures (high and low side). Confirm that you have a healthy compressor.

3) If you have a healthy compressor and an evaporator leak, then bite the bullet and replace the evaporator. And you don't have to use a factory evaporator. Save big bucks and purchase an aftermarket unit with copper tubes. My M-B dealer long ago acknowledged the evaporator problem (unlike MBNA) and began to offer a choice of factory or aftermarket evaporators. If your suction manifold assembly is leaking, replace it. But with an aftermarket remanufactured unit; its available at a fraction of the price of a new manifold.

4. Ensure that the balance of your system is thoroughly flushed. Its the only way to get your system's oil level to zero so that you can accurately load the factory specified quantity.

5. Replace the receiver/drier. Period. No questions asked. And replace the expansion valve and freon pressure switches, even if they aren't leaking. They will eventually. They're inexpensive and installation time is minimal.

6. Refrigerant? R-12 is still available. If you can stomach the price, use it. With the upgraded evaporator and new style expansion valve and freon pressure switches the system should remain leak free for several years. R-134a typically requires a larger evaporator to offer cooling comparable to R-12; in the heat of Miami's summer R-12 will offer the best cooling from a factory stock system. Additionally, R-134a requires higher pressures; a compromised compressor will eventually fail under the additional load.

7. Regarding your concerns about someone messing around under the dash ... no need to worry. Just make sure you go to a reputable, high volume repair facility, whether dealer or aftermarket. So many W124s have sprung evaporator leaks that techs are quite familiar with the repair procedure. Ask for one who has handled a substantial number. One won't be difficult to find.

8. Feel Lucky? Real Lucky? - Take the car to your dealer for a A/C system check. If the diagnosis is a leaking evaporator, request that they repair it for free. After they decline, call MBNA Customer Assistance Center (201.476.6212) and complain. MBNA has been silently performing out-of-warranty ("Good Will") evaporator repairs for years. On W124, W140 and R129 vehicles. In some cases, they cover everything; in others, parts only; or some combination. At this point, you probably don't stand a chance with a 10 year old vehicle, but your odds wil improve if you are the original owner, had all or the majority of the vehicle's maintenance performed by a dealer and previously complained about poor A/C cooling related to freon loss. MBNA will assign a Field Service Rep to inspect your claim; the Field Rep will make a recommendation after reviewing the vehicle's records. The Rep's decision is final and normally cannot be appealed. There appears to be no rhyme or reason to the decision making process; perhaps there is a quota: in one case a friend's '92 400 E out of warranty evaporator repair was paid for in full by MBNA; a week later another's '92 300 D 2.5 was declined. If the Rep says no, then ***** at the dealer. I am aware of one case ('91 300 D 2.5) in which the Rep denied the claim but the dealer subsquently offered the owner the parts at cost and reduced the labor charge from 16 to 10 hours.

Given the number of vehicles that have suffered this problem, I am surprised that a class action suit has never surfaced. Early W140 owners suffered front end problems which resulted in legal action and a settlement with MBNA. All three of my W124s ('87 300 TD, '90 300 D 2.5, '92 300D 2.5) developed evaporator leaks, with the earliest occurring at 55K miles. A friend's '91 500 SL starting leaking at 32K; another's '92 500 SL, at 46K miles. In all, I can tally 27 W124 and R129 vehicles of family, friends or colleagues, encompassing MY '86-'95, that have developed evaporator leaks; most leaks occurred before 75K miles.

This information is culled from my own experiences and is offered with the hope of being beneficial and that a moderator will step in and correct any inaccuracies that may exist.

Good luck.

[This message has been edited by jgl1 (edited 04-08-2000).]

I haven't been able to find anyone that claims to have any experience with Cryoseal on a car like mine, and I don't think I will try it unless I can find someone who will give me some sort of strong assurance.

I do appreciate all the advice on this. I will definitely install a copper evaporator if I replace it, but R12 is not available to anyone except people who stick you for a minimum of $150 just to recharge it. I HATE being dependent on such situations.

A assume that in the meanime, I can recharge this witl a can of oil and a can of Freon 134a on a temporary basis, without any majot problems.

Apparently, the MB system is less reliable than the one on my Hyundai Excel (the model they sold in pairs), as the 89 Hyundai has needed only a new AC hose since 1989. I bought it from the original owner. So far it has 89K ansd the original brakes. But it DOES ride like a Hyundai. The Mercedes is a joy to drive. The Hyundai is a lot better than a 51`Chevy, but less fun. I bought it to avoid having to rent cars when mine needed work,for $250.00.

I have had bad luck with every dealer I have ever dealt with, not just in Miami, but in Seattle, Kansas City, West Virginia and Maryland. All overpriced, all slow, all horrid liars. I know for a fact that two of the salespeople at Warren Henry are impossible smartasses. Of course, salespeople are usually smartasses in the US.I noticed that in the dealership, a customer who wanted to talk with the mechanic was told that the mechanic was busy. At the local Mercedes independent shop I can talk with the mechanic, which I consider pretty much essential.

I bought this car last year from the second owner, who owned it since 1992.

Incidentally, when the AC was working well, it would cut off and blow uncooled air about every 20 minues for about 45 seconds, then blow cold again. I was told that this has something to do with a selector switch. At one point it began blowing hot air. This turned out, I was told, to be due to a false contact in the fusebox. It didn't cost extra to fix it, so I assume that this is correct.
I don't suppose that the switch could be related to the very small leak the mechanic said he detected under the dash? I suppose some sorts of switches could in fact leak.

Richard, did I understand you to say that you were going to mix r-12 and r-134 in the same system?? You could be asking for bigger problems by topping up an r-12 system with r-134. If you are going to use r-134 there are a lot of other things you would have to do before making the switch to the other refrigerant. It's not a simple drop and swap operation. There a a number of other posts about this topic. Do a search, and beware of easy quick fixes..

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Jeff L
1987 300e
1989 300e
1987 BMW 325

[This message has been edited by jeffsr (edited 04-09-2000).]

Sorry, I forgot to mention that I have previusly converted the system over to R-134a. I had this done at a MB shop, and it works fine, except for the leak.

I realize that R134a and R12 cannot be mixed.
I have been checking previous posts on this. I am unlikely to do this myself, but can anyone recommend a good book on auto AC's?

Does anyone know the Mercedes Benz North America customer service number...the number listed in this thread seems to be to a fax machine.

posted in thread as .....
"....call MBNA Customer Assistance Center (201.476.6212)...."

Here is a very useful place, wih some very useful info like this forum..

http://www.ackits.com/

There is an AC forum with some very knowledgeable folks...

__________________
89 300SEL Money Pit

92 Blown Buick Ultra Pimpmobile 220K and adding 1K per week

88 Wagoneer Slightly modified (Not for soccer moms)

04 Kia Sedona with every option... NICE

Sealer when recovered into an unsuspecting a/c shops machine will really mess up the machine, sticking solenoids and other nasty things. I really hate to see it used.

There is so much junk refrigerant in systems that the shops now have to be out the expense and time of using an identifier before recovering to keep from spoiling a whole cannister of refrigerant. Now it is getting to the point that they will have to buy and use sealant detectors as well. That cost, of course, has to be passed on to their customers if they are to stay in business and continue to be able to afford shoes for the baby.

Have a great day,

Hey folks, this is a three year old thread.


neumann - call 1-800-For-Mercedes. They'll direct you to the right place.

__________________
Rick Miley
2014 Tesla Model S
2018 Tesla Model 3
2017 Nissan LEAF
Former MB: 99 E300, 86 190E 2.3, 87 300E, 80 240D, 82 204D Euro
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