1949 Frigidaire DL-86P Not Cooling

That's a very nice looking fridge! 

As far as the troubleshooting, I think you're on the right track. For the tubing, I doubt that a pinhole repair would require replacement of tubing, so you may not have to face that aspect of things. The issue will be, as you said, locating the leak. It may have leaked out over years, and there is no longer any pressure to see bubbles. 

It's getting harder and harder to get hermetic service kits. It seems that most of them get bought up as soon as they appear on eBay. You could wait for that, or possibly install a soldered-in service valve on the return line, as opposed to a piercing valve. The soldered in valves are more of a permanent and professional solution. They work like a tee-fitting, where you would cut the line and insert the tee, and then solder it into the newly cut line.

If you do have to replace any lines, it's best to go with the same size, if possible. It's OK to go smaller or larger for an inch or two, for connection purposes, though.

I would inspect the evaporator closely, for any puncture marks from a previous incorrect defrosting job. That could be the most likely area for leaks.  Another possibility is that the compressor terminal seals are seeping and allowed the charge to get lost via that path. You would see oil around the terminals, if that were the case.

For refrigerant, it is a poor choice to use R134A for these for a variety of reasons. The pressure is much higher than the unit is designed for; and the discharge temperature is also going to be excessive. Either go with R12 or R152A. And never use any sort of blended refrigerant because those contain propane and butane which will separate in the system and, worse, will soften and destroy the rubber seals in the compressor. 

Hope this gets you some ideas to go on! 
Sincerely,
David

That's good! Feel free to keep us updated. 

Hi Rich. Sorry I have been on a work site and have little time for Internet stuff.

The high current draw almost sounds like a wiring error with the start-relay. How did you detemrine the R, S, and C of the new relay?

If not that, it could be that a major overcharge of refrigerant has happened. But that wouldn't cause overloading immediately. That would require the compressor to be fully warmed up before it overloaded things.

How long did it take for the current to get too high?

The compressor appears to be an R12 unit based on the weld seam at the top, and the factory service port located at the top of the compressor housing. There is a chance that it could have been some transitional model which looked like the R12 models but was designed for R114 which operates at a lower pressure. In that case, you can probably use R152A but it will require a reduced charge volume. Ideally, R1234ZE would be a better R114 replacement. Is there any legible nameplate with a refrigerant identification marking?

Cool. I am a problem solver for the company I work for but sometimes the problems are caused by other peoples' stubbornness and ignorance! That is harder to fix than any technical problems!

If the compressor is overcharged but otherwise everything is connected correctly, it will build up to an overload over a period of several minutes running. The immediate overload indicates an electrical problem.

The compressor should have the three terminals facing the rear of the cabinet. When you face the rear of the cabinet, your left-most terminal is the Com terminal. The middle one is Start and the right-most one is Run.

You can measure the resistance of them in order to verify.  

When used with an RO81, it will draw 10 amps or so for about 2 or 3 seconds, then settle down to about 2 amps. If it continues drawing high amps, there's something wrong with the wiring, or the RO81 may have an internal problem. 

This diagram shows how an R12 Meter- Miser and RO81 connect together. You can ignore the rest of the wiring and just focus on the Supco device and the compressor.



Hope this helps!
Sincerely,
David

Thank you for taking the time to put together that diagram!

I've never been able to master the politics of people and it certainly is a harder problem to solve.  

I wouldn't have been able to resurrect this machine without you.  If I can ever repay the favor in some way, I certainly will.

Cheers,
Rich

Well I'm back again! The refrigerator is really taking shape and I am so pleased. I ran the unit overnight and I am concerned because the refrigerator is not cycling off.

I dismantled the thermostat and put everything into the sonic cleaner. Everything seems to be in good order. The capillary tube does not appear to be broken anywhere. I put the entire thermostat in a freezer and then removed it. The billow did expand the contacts closed as it became warmer. I'm not certain if that's because the entire unit was in the freezer though.

I reinstalled the thermostat and ran it on the C setting and I believe it cycled off. I examined my stem thermometer and the temperature read 19 degrees. Perhaps it's set improperly? Is it possible to make any adjustments? I only noticed it cycle off once, so perhaps the overload kicked in for some reason. When I turn off the unit on the dial, there is a stange sound from the evaporator. I attached a video and pictures of the internal temperature.


IMG_7325.mov (18.66 MB)

I'm sorry, I meant on the outside of the liner and follow the suction line to the freezer!