On the subject of charging the ac and slow evaporator leaks - do any of the sealants which are added via the charging kits any good?

Please provide brand name recommendations.

Do these sealants cause any damage to the internal ac parts and compresor?

Last Summer I had to add a pound of freon and its been good to go ever since.

However, I strongly sustpect a slow evaporator leak - despite the fact I had it already replaced once under warranty at 24,000 miles ( now have 57,000 miles).

hi, Nathan.

I tried the sealant that comes with the charging kit, it did not work for me. I put in a sealant by cryochem at cryochem.com. This was at the end of 7/00 and its still working fine after an initial loss of freon while the sealant filled the leaks presumably. Read their info no their web site for 134a stuff, the 850 evaporators seem like a prime canidate for this stuff. One note, its not cheap, $128 or so, but weight that against the price of a new evaporator.

Steve -

I checked the web site for cryochem and they indicate that you need to be EPA certified to order the product. Did you order direct from them or go to one of the distributor? Like they say Firestone is a distributor so would one to to them and have them do it?

Hi Ken.

I am sorry for not writing sooner to your question.

I called cryochem to find a local distibutor, I then called (30 miles away) the local distributor and they were not customer friendly, they would not sell it to me thinking epa, and thier price was a 100% mark up if they put it in, plus labor. I then called cryochem back and told them about it and asked them what the deal is with the EPA certification, you can buy r-134a at K-mart, and is not a controlled freon like r-12 is now. They (cryochem) agreed to ship it directly to me via ups.

I also recieved an e-mail from Rob asking about the replacement of the a/c system dryer, Cryochem suggests that you replace it if it has been contaminated with moisture by having the system not working because of a leak that has introduced moisture, the sealant works by hardening on contact with moisture and air when it leaks out, there by sealing the leak, haveing moisture in your dryer would be bad news, my system had a slow leak and I kept filling it as it would lose its effeciency, so it was never expose to the atmosphere, I also pulled a vacuum on the system before putting the cryochem sealant in. From what I understand from researching this while I was lokking for a cure to the evaporator leak, is that when the dryer is exposed to the atmosphere it will get saturated with moisture and is virtually ruined from this to preform the function of dryeing the freon system from moisture and condensation.

Is it possible to tell if the dryer needs to be replaced? I got my 850 in November, the A/C worked then (as well as you can tell in November) so maybe it never completely leaked out to the point of letting moisture in, but who knows?

Is the vacuum pump something you can buy or rent, or is it specialized equipment that you either have or you don't? It's hard to find much in the way of instructions on A/C work, other than "take it to a shop".

Hope to see some more evaporator success stories in here soon!

Hi Terry.

The vacuum pump is something most people don't have access to. One simple way to tell if your system has pressure in it is to take off the valve cap of the schrader valve (the a/c system fill valve and is similar to a bicycle tire air valve) that is located on the passenger side either by the fire wall were the a/c system pipes go thru, or in front of the engine compartment inboard of the widshield fluid fill cap (depending on year),and use a nail or real small screwdriver and push on the stem to see if there is pressure. Don't put your face too close when you do this. If there is any presure at all than your syetem should not have been in a state of being open to the atmosphere and allowing moisture in. Also if your a/c compressor is constantly cycling it is low or out of a charge. If you were to get your self ready to use the a/c sealant, I would go to a respected auto a/c place and have them evacuate the system. This will pull a vacuum on the system and then you could put the sealant in,wich should probably be done immediatly after, otherwise the leak in your system will now be allowing moisture in because of the vacuum on it.

Your right on finding out how to work on the a/c system, but ask around, you will probably know someone who has knowledge of car a/c systems. One final thought, the 850's only have a fill valve on the low side of the a/c system. This buged the h out of people at the a/c shop I went to at the start of my a/c situation. Most every other car make has always had one on the high side also.

Hi Steve,

I tried the Walmart/K-mart-type sealant a couple of times and they didn't work.

Have you taken a pressure reading recently? Has it been at the same level since the initial settling?

I have read the website a few times and I'm very interested to try it out this summer. Mine, with or without the cheap sealant, last only about 3 weeks. I think I'll vacuum the line before I put the stuff in.

Thanks!