ReplyIs that OEM size or did u convert it?
Maybe try OEM tube or get exact OEM size
Professional Member*
Turbo aire. TST72sd
long story short evaporator had a leak replaced evaporator capillary tube clogged week later. Changed with supco #3 52" cap tube.. Charged with 19oz. 134a. Unit. Still in at 10hg suction and 110 liquid Box temp 70. Changed spun copper filter blew system out with co2 appeared no clogs...... any advice on next step would be greatly appreciated...
Professional Member*
Is that OEM size or did u convert it?
Maybe try OEM tube or get exact OEM size
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Oh...in case I forgot...turbo aire is absolute crap. Lol
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There all crap!Originally Posted by UmmScott
Is the cap tube bonded to the suction line?
Replace the suction line / cap tube assembly.
Refrigeration Hardware Supply or Case Parts can supply it.
R I P Icemeister
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Professional Member*
this is what you are URI suggested (conversion)....Case has a backorder? Guess ill wait
Tube not bonded coiled up 2 part.......
Regular Guest
Your best bet is replacing a compressor and cap tube, if you go only with cap tube you be back to that call in future. Go with Oem size, I know some of turbo air have metric size cap tubes.
New Guest
What is turbo air and its use?
New Guest
I'm going to school at this time to get my certificate in HVAC.
Professional Member
I do not trust R134a, especially used with cap tubes. In fact one of my schools' food service director asked me for a recommendation of a new pass thru cooler, I advised her NOT R134a.
The issue as taught by Sporlan, is that the POE oil used with R134a breaks down into a waxy substance to clog the cap tube. Replace a clogged cap tube, and/or some torch heat melts the wax, and soon back in a clogged cap tube. Sporlan sells a series of filter driers with a designation of "...-HH". The smallest is bigger than is needed on a cooler such as Turboair, so you willl need to adjust refrigerant level.
Oh, and warn your customer about the wax/cap tube clog AND that it will cause the compressor to run hot which aggravates the wax, and DOES shorten compressor life. (If you replace the cap tube then soon you may face a dead compressor and unhappy customer if you do not warn them.) I have lost count of how many school type milk cooler cap tube and compressor changes I have done. I ALWAYS put in the Sporlan -HH.
Caliboy, Turbo Air is a reach in low budget cooler or freezer, used in commercial kitchens.
Professional Member
If you had a leaking evap there is probably water in the oil and it's freezing at the cap tube outlet. That's why it seems fine when you purge with CO2 and is restricted when running. Change the compressor oil and install an oversized real filter dryer (not spun copper)
Professional Member*
Yup don't use those crappy copper driers...use a quality sporlan HH Capt drier as stated
Professional Member*
Yup, HH drier. Making sure the cap tube is not plugged. On those little units, I always charge through the high side and be sure the suction comes up. More so on the quick down and dirty repairs.
Likely the compressor is still functional if it's pulling down to 10"hg.
Haven't heard about the waxy thing with POE and 134a, interesting. But have never had a problem, and I see a fair amount of True and Turbo Air boxes running 134a.
Professional Member
If the manufacturers would have put TXV's on these crap 134 systems we probably would not be dealing with this curse. Oh well job security.
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Cost my friend....$$$ talks, and cap tubes are cheap and never EVER go out of calibration.
Heck they never restrict or plug....,......................do they? Lol
Professional Member*
Almost Any coil you see thats clogged with a blanket of dust , or grease clogged and had been running this way a while, will almost always be waxed. They get really hot and slowly cook the oil until it creates a wax.
I replace most of the cap tube and add acidaway
Professional Member*
That's wild. I've seen a lot of those little boxes with totally plugged condensers. I think some of those didn't even come with a shroud for the condenser fan. I will literally punch big holes in the side of the cabinet (you know, with the Greenly punch for making holes for electrical fittings) so I can get full access for cleaning those little condenser coils. I'll get them shinny and virtually spotless.
Turn the unit back on and make sure the condenser return bends are the correct temp. Most of them are pretty old and still have the factory crimped access tubes, so you can't even check pressures. If the condenser is the proper temp, and the suction at the compressor is cool, I just tell the food service folks to let it run for a couple of days and if they don't like the temps, put in another trouble call.
Of course, I put the usual disclaimers on the invoice to protect myself. Maybe the cap tubes are a bit restricted. But most of these units are getting on in the years. You just don't want to put much time into them. And as long as the compressor is still getting enough cooling from the returning vapor, I'm happy.
Don't think I've ever had a call back from cleaning a totally plugged condenser on one of those.
Professional Member
Theres something beyond heat that causes the wax. I have seen others speculate that its moisture from the factory or different oils etc. I have a customer that has 3 True bottle coolers built into their bar in a way that they get no air flow. The compressors cycle on the overloads more often then they cycle on the T-stat. The liquid lines are so hot you can't touch them. I replaced the overloads multiple times because they couldn't take cycling that much. After 6 years of that abuse one compressor finally kicked the bucket 2 weeks ago. I changed it out and the cap tube was perfectly clear and the new compressor ran perfect pressures with the old cap tube.
I have seen units that have been treated much better and still clogged the tube
Professional Member*
Yeah, they figured out how to remove the wax from oil several decades ago. And I doubt the refrigerant is contributing to a waxy condition. I don't disagree that cap tubes are getting restricted, but the link between 134a and POE oil is something I am not convinced of yet.
But I still take interest in the discussion. If something is going on, I'm all ears . . .
Professional Member
POE never had wax in it, so really what we see is a "waxy type substance". Someone here once said its a salt.
Professional Member*
We call it wax , but you cant really test it .
You cut the cap tube as it exits the drier , and you look inside tube to see nothing but white clog
Im not sure how you would remove some to test what it actually is ...
But thats pretty amazing how Craig has a unit that constantly cooks itsself and never clogs up. Interesting.
Almost 50 percent of the ones I come across with a filthy cond coil , I clean it , then soon after I will get a call back with no cool. Diagnose , clogged cap.
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