I have a Coleman Mach 11K unit that has been blowing warmer and warmer for about a year now. The **** thing is only 3 years old with VERY little use. Can't be expected to buy a new one already, right? It finally quit blowing cold this weekend. Went on top to check all the normal stuff. Caps tested good. Compressor is clearly working hard as it gets super hot with no condensation accumulating anywhere. Low side is no where near being cool. So....I snooped around online and found out you can repair these things even though they're marketed as "unserviceable". I bought a Supco bullet service port to install inline on the low side, BUT I first need to find the leak and determine how bad it is and whether dumping in refrigerant/sealant/oil will do the trick. Problem is, where do I find this R410a? It isn't exactly like you go to Walmart and pick some up. Where would I find it without paying a fortune?

I will assume You have the proper gauges etc. for the job and are familiar with the dangers of high side versus low side, know how to draw a vacuum in the lines etc. Amazon, Ebay both carry the refrigerant you specified. Ebay has smaller containers with stop leak in it. Either way it ain't cheap

I hope you realize that you also need a vacuum pump (a fairly healthy one) to evacuate the system before you pump a full charge of freon back into it.Then.....leaks are most often located by putting a little freon in and using an electronic "sniffer" to find the leak.What if the leak turns out to be in the compressor ? Or in the evaporator or condensor ??Layman attempts to fix "non-servicable" refrigeration units usually turn out bad......with the best ones just wasting time and money.....and the worst ones ending up with injuries.

As a suggestion, you might want to install the service port and determine if there is any charge left. I'm assuming you have a leak tester? Using soapy water hardly gets it as there are too many places hard to see. If it's completely empty (probably) you could get a can of 134A (automobile refrigerant) and charge it with that just to find the leak. This would be cheaper than chasing down the 410 and wasting it for leak testing purposes. You are going to have to evacuate it to fix it anyway so the 134 will go away. I'm thinking you will find out why they are called 'unserviceable'. Usually these units last a long time...you just drew the short straw. If you have "Big Lots" stores near you, they are frequently the cheapest place to get 134A.

You assume correctly.I wasn't able to find anything but the 25 lb. tanks on amazon. I'll have to check ebay. What a complete bummer to have this newish A/C fail. I have a mind to complain to Airexcel, but that'll probably get me no where.

Do not use any stop leak or products with stop leak. If you ever plan on having a shop service a a/c unit after you have used it. As they will probably need to replace most of the components in the system. That stuff is real nasty. It does stop leaks.

Anyone Recharged Their A/C Refrigerant? | Good Sam Community

joeshmoe
Explorer
Jul 15, 2017
wa8yxm wrote:
If charging is needed you can recharge.. But let me ask this

Did you clean the condenser coils?

I did mine last week (or was it the week.. No it was last week)

Yep. First thing I checked.
MEXICOWANDERER
Explorer
Jul 15, 2017
If the leak is due to a rotating shaft seal failure, operating the unit every couple of months in the off-season may help.
garyemunson
Explorer II
Jul 15, 2017
I wasn't advocating running the system with 134, just using it for leak test purposes since it's much cheaper. I use a 'sniffer' to locate leaks, myself.
dougrainer
Nomad
Jul 15, 2017
MEXICOWANDERER wrote:
If the leak is due to a rotating shaft seal failure, operating the unit every couple of months in the off-season may help.

Explain this. The Roof AC systems are SEALED. Doug
ken56
Explorer
Jul 15, 2017
The only place you are going to get 410A is with a heating and cooling business. Ports will have to be soldered in and the system evacuated and moisture boiled out and Then refilled with proper refrigerant. DO NOT use 134 to find the leak. That will contaminate the system and another procedure will have to be done to clean it out. Its quite involved and if you do it then take it off the roof and into a shop to do all the work.
Twomed
Explorer
Jul 15, 2017
ken56 wrote:
take it off the roof and into a shop to do all the work.

I did this down in the Keys...high $$ area. Obvious leak spot. Two Schraders, dry and recharge...$170.

Five years and going strong. I was happy!! Good Luck.
Pauljdav
Explorer
Jul 15, 2017
Probably the the leak is at the compressor.
Sam_Spade
Explorer
Jul 15, 2017
garyemunson wrote:
As a suggestion, you might want to install the service port and determine if there is any charge left.

And just exactly HOW would you go about installing a service port WITHOUT letting all of the charge leak out ???? and letting air IN ????

The only practical thing to do here is:
Call around to a few HVAC companies and see if any of them will service a non-servicable unit like that. Be prepared to give them the make and model.

Some of them CAN be serviced.....and with some it's just not practical, even for a professional.
Kayteg1
Explorer II
Jul 15, 2017
I bought $7000 refrigerator in good condition for $200 because owners hear stories like above.
$12 for clamp-on valve on the net, refrigerator uses R134 that I already had for my cars and the fridge run perfectly for 2 years before it needed another $5 of refrigerant.
You don't need 2 valves. Just find source of refrigerant, the charging gauges cost $60 at HFT sale and go.
All you have to loose is about 1 hr of your time.
Bob_Landry
Explorer
Jul 16, 2017
For the future benefit of those who do not understand RV air conditioning but just want to post something, these compressors are hermetically sealed units. There are no shaft seals to leak, they do not leak, and they are (the compressors) are not serviceable, only replaceable.
Also, you can not recharge these units by simply adding refrigerant until the suction line sweats back to the compressor like you could with R22. You have to charge by scale, charging cylinder, or by super-heat measurements. You would also have to install two service ports. If you do not have the converter device that allows you to charge with vapor, you have to charge with liquid on the high pressure side. If you do not already know and understand this, you should leave it to the pros.

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