Anyone Recharged Their A/C Refrigerant?

[joeshmoe]

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?

[Bob_Landry]

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.

[Kayteg1]

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.

[Sam_Spade]

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.

[Pauljdav]

Probably the the leak is at the compressor.

[Twomed]

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.

[ken56]

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.

[dougrainer]

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

[garyemunson]

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.

[MEXICOWANDERER]

If the leak is due to a rotating shaft seal failure, operating the unit every couple of months in the off-season may help.

[joeshmoe]

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.

[joeshmoe]

dougrainer wrote:
1. Taps are NOT a good tool. They WILL leak. Soldering in a Schrader valve(Hi and Low) is best.
2. The system only holds about 16oz of 410. So, buying a few lbs will be hard to do.
3. They are called NOT Serviceable because they are sealed systems and have NO fill ports. You CAN service them, but the cost is high. Due to NOT having 410 easily available and you need to solder in the 2 service ports and have a Dial A Charge. AND know how to use a Dial a Charge to get the proper amount of LIQUID 410 in the system. You can charge by amp draw based on ambient Temp correction, but you need to know how to do it. Doug

My initial thought of these taps were the same. Not a good idea. Taps, in general, are bad. I'm a plumber, so I can sweat in a couple valves.

I have an idea where the leak could be. There's an obvious oily spot near the front of the unit.

[wa8yxm]

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)

[Johno02]

Cheaper to replace than repair. (Unless you are in the AC repair business and have the tools and equipment).

[dougrainer]

1. Taps are NOT a good tool. They WILL leak. Soldering in a Schrader valve(Hi and Low) is best.
2. The system only holds about 16oz of 410. So, buying a few lbs will be hard to do.
3. They are called NOT Serviceable because they are sealed systems and have NO fill ports. You CAN service them, but the cost is high. Due to NOT having 410 easily available and you need to solder in the 2 service ports and have a Dial A Charge. AND know how to use a Dial a Charge to get the proper amount of LIQUID 410 in the system. You can charge by amp draw based on ambient Temp correction, but you need to know how to do it. Doug