Leaking sight Glass!?!!

[The MG Pony]

Well today I was charged with taking out an old plant from an old sandwich cooler. So I removed the plant and be for cleaning it up I was told to check it. So I pulled a vac (The unit had leaked dry) and it actually held just fine, So I tested and noticed pressure wasn't holding well (But yet it held a vac!) So I went through and tested each part with soap water and BANG found the sight Glass bubbling away. I never seen this be for, How often does that occur?

I swapped out with a new sight glass and F/D and it's purring away, but was rather curious that a sight glass was leaking!

[lana]

Hi The MG Pony,
I once had leakage form a sight glass on a receiver. This sight glass was flare type (the glass part).
Otherwise not seen leakage from them.
Cheers

[The MG Pony]

Ya thats where it was leaking from! Around the glass It was a R-134a system so pressur wasn't even that high! Orrigionaly R-12 but the tech who last worked on it replaced the sight glass comp, and F/D.

[malik55]

The MG pony
Sight glass do leaks due to gaskets, you have already replaced with a new one, Why not open old one and check it,
malik55

[monkey spanners]

Took this picture of a sight glass last week. Believe it or not it was'nt leaking.

Cheers Jon

[ianybeany]

When you say it held a vac, was this on a proper torr or milli bar gauge, and for how long?

[Brian_UK]

It could hold a vacuum as the seal can get pulled into/onto the mating surfaces/threads.

[The MG Pony]

800 mTorr for a fiew minutes (Ya My pump is gimped I think)

[wkd]

Brian is right ,have seen this many times on package chillers.

[taz24]

So I went through and tested each part with soap water and BANG found the sight Glass bubbling away. I never seen this be for, How often does that occur?

I swapped out with a new sight glass and F/D and it's purring away, but was rather curious that a sight glass was leaking!

Quite a common fault.
It did not show on the vac as others stated because it pulled itself in and sealed.
Now you've found it once you will Know to look for it again

Cheers taz.

[The MG Pony]

Ya, first time for me too never would have sustected a sight glass, a drip fell on it as I moved the brush to the other flare and noticed slight bubles so put a full drop on and well!