TK SBIII Leak Testing

[ihdiesel]

Greetings. I am trying to locate a refrigerant leak on a TK reefer unit. This unit was built in 2000 and has R404A. I have been using a Robinair 16600 leak detector along with soap and water trying to locate the problem with no luck.

What is the best method to use to find leaks on this unit?

Is there a better leak detector for R404A?

Thanks in advance

[moggy66]

I would reclaim whats left...pressure test with nitrogen......

[DaButcher]

Couple pounds of R22 along with dry nitrogen and your leak detector should do it

[fridgability]

Possibly leaking from compressor shaft seal. You cant get the leak detector close enough to register, look for traces of clean oil at bottom of clutch housing. Most often leaks on SB's I have found are from manifold gaskets and Throttling valve. (Remove the rubber gaiter from the valve and snif at the small breather hole). Also the Defrost tray heater pipe sometimes corrodes into pin holes. Good luck.

[sedgy]

hi diesel , why not get a tec in to fix the problem
da bucher, why use a ozone depleating gas to find a leak? is that why there are no poler bears in texas ?

[DaButcher]

hi diesel , why not get a tec in to fix the problem
da bucher, why use a ozone depleating gas to find a leak? is that why there are no poler bears in texas ?


It is not recommended to add nitrogen to R404A for leak checking............You're right there are no Poler bears here, if R22 is the reason, maybe we should vent more of it

[ihdiesel]

I would reclaim whats left...pressure test with nitrogen......


Couple pounds of R22 along with dry nitrogen and your leak detector should do it

at this point I don't have the equipment to pressure test with nitrogen. I will check into it as it sounds like a good investment / addition to what I have now, and would likely get used in the future. Any recommendations?

Could R134A be used instead of R22?



Possibly leaking from compressor shaft seal. You cant get the leak detector close enough to register, look for traces of clean oil at bottom of clutch housing. Most often leaks on SB's I have found are from manifold gaskets and Throttling valve. (Remove the rubber gaiter from the valve and snif at the small breather hole). Also the Defrost tray heater pipe sometimes corrodes into pin holes. Good luck.

I have checked everything you mentioned. I will take a closer look at the shaft seal. There are a couple small worn spots on the tray heater pipe where the clamp was loose, but I was not able to confirm a leak there with soap and water. I will check that area again.




hi diesel , why not get a tec in to fix the problem

In the past I have done everything except the refrigeration system myself. A recent experience having a VERY poor repair job done by a TK dealer makes me think I can do better myself, or at least I should try to muddle my way through before seeking professional help.



da bucher, why use a ozone depleating gas to find a leak? is that why there are no poler bears in texas ?


It is not recommended to add nitrogen to R404A for leak checking............You're right there are no Poler bears here, if R22 is the reason, maybe we should vent more of it

If I understand the theory here the idea is to use a refrigerant with a smaller molecule pressurized with OFN for the test to make it easier to locate or pinpoint the leak and will also be a little more sensitive to the test equipment.

wouldn't the procedure be to reclaim the nitrogen / R22 test mix, or is it normally vented?

Thanks so much for all the help everyone!

[sedgy]

hidiesel , yes it was done < using fridge gas to find the leak , but it must be 10 years since I had to add ozone depleating gas to ofn to find a leak, if you can get to the compleat system you only need to add enough ofn to show where the leak is,
obviesly now and then you find a system that dont give you a clue, so then you could use helium< non ozone depleating gas < to find the leak<
I allways thought I was a castodium , by not poluting the atmosphear, but it apears not all tecs have this afinaty
and I am very sad , for them and possibly the world. can anyone tell me I am wrong?

[moggy66]

wouldn't the procedure be to reclaim the nitrogen / R22 test mix, or is it normally vented?


Vent it....I must admit i am not a great fan of mixing ***** with nitrogen for obvious reasons

[DaButcher]

We are getting off topic somewhat here but R22 and nitrogen is an acceptable method of leak detection.

Below is quoted from http://www.aircondition.com/knowledge_base/LeakDetection/OtherMethods.html

R-22 summary. R-22: (a) creates a leak path because of its oil solubility and residue displacement potential; (b) is more readily detectible by electronic leak detectors than HFCs; (c) is non visual-dependent, unlike dyes, thus can be used effectively to locate leaks in enclosed areas; (d) will not cross-contaminate nor cause any harmful consequences to CFC, HFC, nor blend refrigerant systems (i.e., after leak testing an HFC (R-134a) system using R-22, there is typically zero percent cross-contamination if evacuated afterwards).

R22-nitrogen test mix used for leak testing is not considered a refrigerant and therefore may be released to atmosphere. Their rationale is that one tiny loss which results in the discovery and repair of a leak reduces the greater loss over the life of a system. It’s better than multiple recharges of refrigerant and multiple losses to atmosphere.

[cadwaladr]

he could always put a dye in the system yellow jacket make catridges its easy to spot with the correct torch,

[paulitoplf]

lo mejor para encontrar una fuga en refrigeracion es paciencia y observacion

[abbsnowman]

lo mejor para encontrar una fuga en refrigeracion es paciencia y observacion



Huh? :eek:


Diesel, without nitrogen and a micro gauge, your dead in the water buddy.
Cad, that stuff makes a heck of a mess!
Dabutch, good on ya for trying to help!