Cav 72 Cooling Issues

[SodaShopNick]

About a year ago I picked up an unrestored Cavalier 72 machine which was actually in pretty good shape and has been running in my garage ever since (ice cold drinks!!).  That is until about a month ago when I noticed the temperature seem to not be as cold, but when I would check back hours later it would be icy cold again.  As the month went on the time between icy cold and not so cold got closer together.  Finally a few days ago after being icy cold for some time the evaporator started to blow out warm air.  The funny thing is I can unplug it, let it sit for a few hours, plug it back in and within a few hours it is ice cold again.  Then after about 6-8 hours we are back at warm air.  In conjunction the compressor seems to be staying on for a long time, probably about 4-5 hours when initially plugged in, then finally kicked off.   Both fans are working and the condenser and evaporator look pretty clean.  Any idea what the issue might be?   As always I appreciate everyone's help.

[MoonDawg]

     You have moisture in the system. It travels just fine through the lines intil it becomes a water droplet and freezes, clogging the line.

[SodaShopNick]

Moondawg,

Thanks, what causes the moisture?  Is there a leak somewhere?  Should I have a certified refrigeration person look at it?

Thanks,
Nick

[SodaShopNick]

Just checking in again.  So does moisture in the system mean there is a leak somewhere that I need to have a certified tech come out and take a look at?

Thanks

[johnieG]

Typically yes, it's usually a leak in system that can cause the internal pressure to drop below atmospheric & draw in air & humidity, it can also be introduce through leaking clamp-on style tap-valves or even original service valves, ( I had one the other day, a brand new, out of the box 1/4 HP Tecumseh with a bad valve stem seal) also through poor repair techniques. or contaminated recycled refrigerant in some cases, the filter/dryer can handle some of it, that is until it becomes saturated & the water migrates into the system oil & pulls it's little "freeze at the capillary tube opening trick" it can also cause the oil to become acidic & eat the system from the inside out.

[SodaShopNick]

Johnny G,

That's interesting about the brand new system. It looks like I will need to get someone out here to take a look at it. 

Thanks as you guys are always so helpful....especially to us beginners.