New Guy with a Cav USS-8-64

[LaGattaDJ]

New Guy here,

 I recently obtained a Cav USS-8-64 found on facebook in the Albany, NY area.  It was advertised for $250 but was able to get it for $150.  I wasn't originally going to make the trip as it's an hour and a half from my house but the seller was kind enough to meet me half way.....this should have set alarm bells off in my head, but being a guy who is honest and has integrity I was thinking, or hoping the seller did as well.  Wrong.  Anyway, I asked the usual questions, does it vend, make change, cool, keep temperature, cycle, etc. etc. etc., received affirmatives after each question so I threw caution to the wind.................I got the machine home, plugged it in after letting it stand upright for 24 plus hours and the GFCI breaker kicked immediately......hmmmm.  I tracked down a direct short between neutral and hot on the condenser fan motor. I disabled the motor by unplugging it from the harness and plugged it back in, compressor kicked on, took over two hours to reach 38 degrees in the cabinet, not good, wouldn't cycle off on the lowest thermostat setting. I did have an auxiliary fan cooling the condenser and compressor. OK, so something's incorrect with the cooling, more on that later.  I turned my attention to all of the other systems, micro switch on bottle rack wired incorrectly, fixed, bad bottle release solenoid, replaced, NRI coin mech not working, took three hours but all cleaned and adjusted and lubricated, "Have a Coke" light and "Use correct change" light sockets were in wrong places, quick fix,  marque light fixed and am waiting on a ballast for the bottle door fluorescent.  Now that the machine can function as it should I had a tough decision to make.

In 1985, 86 and 87 starting at 19 years old I worked for Coca-Cola on the night crew loading route trucks.  At that time the life of the refillable bottle vendors was coming to an end and they were coming into the plant in droves.  Being on the night crew, once the asset tags were removed and the old machines were tossed in the scrap pile, we figured they were fair game.  A few made it into the back of my 1980 Jeep CJ-5 (what a sight that must have been). Anyway, I've managed to hold on to a Cav CSS-8-64 all these years, cools great and have had beer in it for many, many years.  Wife is a big Diet Coke drinker so the USS machine was attractive to me because it can vend 16oz. plastic and 12 oz. cans. 

Soooo, Do I take the compressor deck out of the CSS and transplant it into the USS?  Yes, that's just what I did.  Machine is perfectly functional now! 

So, after my long winded intro, the old deck is on a wood stand awaiting servicing.  My questions:

     1.  Compressor starts and runs no problems, what are the chances over the years a bit of R-12 has escaped?  Seems odd that it would as its a sealed system.

     2.  Compressor runs quiet, what are the chances the compressor is weak and needs to be replaced?

     3.  Evaporator and evap fan are fine, clean as a whistle, I don't think if the compressor is replaced I'll need to replace the evaporator, agree or disagree?

     4.  I have a friend that is a refrigeration tech and will lend me his gauges, where can I find the correct pressure points? He will assist me but I want to learn.

     5.  Does anyone have a service manual for the Cav USS-8-64?

Sorry for the continuing on and on and I hope my introduction was appropriate in this category as I didn't notice an introduction area.

By the way, I am an Industrial Arts teacher and have above average mechanical ability and am not afraid to learn something new and just happen to have a few cans of R-12 kicking around.

Thanks for reading my novel and I look forward to your responses.

Dave

Oh, I realize you all like pictures  Keep in mind, my intentions are not to restore, only enjoy a good ole garage machine that functions.  Attached are pictures of my CSS-8-64 which I've had for 32 years and my newly acquired USS machine.

[MoonDawg]

        Welcome to the group Dave, you have become addicted like the rest of us. 
The reason they make parts machines is for guys like us. Most Cavaliers use the same system so any glass door rust bucket should get your other machine back up and running.
       In the meantime, you should check into getting your refrigeration certificate online. $30.00 and study at your own pace. It's a great way to learn.
An inexpensive vacuum pump, gauges, a torch and a few hand tools and you will be able to fix most of your own machines.

[LaGattaDJ]

Thanks for the welcome!

I installed a Supco clamp-on service port to the suction side and hooked the gauges up.  I had a static reading of 35psi. As soon as I plugged the machine in the needle in the gauge pulled down to about 13psi.  As a note, the machine hadn't been running when I did this test so it was room temperature.  I let the machine run a few minutes, the copper line in the refrigerated area of the machine that attaches to the evaporator started to sweat a bit and got cool, not cold, just cool, the capillary tube was what felt a bit cooler than room temp where it enters the evap.  It sounds like gas is running through the lines.  Can anyone help me interpret this?

[MoonDawg]

       Johnie G may correct me, but I'd say you have a clogged filter/dryer.

[johnieG]

Hmmm, you must have a very cold " room temperature"  because 35/psi would be aprox. around 37-F  in a temperature vs pressure relationship based on R12.

Sounds like a plain old fasion undercharge situation to me at first glance.  Ie: you have a leak somewhere.

So what was the ambient temperature when you first put your gauges onto the system / low side line?

Here's a handy temp vs pressure reference guide...

http://www.ref-wiki.com/data-for-freon.html

[LaGattaDJ]

JohnieG,

It was about 75 degrees and extremely humid in the garage.

[johnieG]

Then the chart shows @ 70-F the system equalized pressure should be aprox. Between 70- 76/psi pressure assuming the units been sitting there quietly and has reached the ambient temperature (hasn't been running)

Regardless, 35/ psi is simply too low for R12.