Pressure testing a compressor

[bohica2xo]

And yet you are satisfied with a 200 psi test.

[wptski]

And yet you are satisfied with a 200 psi test.

I'm not knowledgeable enough to decide. It seems nobody in this forum has ever done this before otherwise I would have received suggestions. Are you going to make a suggestion? The 200psi value is aimed at HVAC not MVAC.

The first time this whole system held 150psi overnight. Using a micron gauge held below 500 microns the HVAC standard but had a puddle of oil from the compressor shaft seal come the first spring. There was a user here before(iceman2555) or something like that stated that new seal can leak until run about 10 hrs. I recharged again in that spring but micron readings weren't that good as before and drove the heck out of it but ended up with another puddle of oil.

[wptski]

The compressor was installed again but the "system" won't hold hydrogen at 150psi or 100psi over night. The first time the compressor was out I put new gaskets and shaft seal. The gasket kit clearly came with the incorrect size "O" rings for the manifold so I had a "O" ring kit from ACKITS and used a couple of them.

I don't remember if I left it at 150psi over night the last time and I didn't have an hydrogen setup the first time.

I definitely had a shaft leak but maybe I had a small leak(s) after the first install? I'm starting to rethink one issue, manifold "O" rings. There is conflicting info out there stating if the HR6 uses oval shaped "O" rings after 1988, this being on a 1990 Buick. I'll have to look at the OEM "O" rings as I still have them marked with a twist tie.

Anybody know as the oval "O" rings? Might be tough to find if needed!

[GM Tech]

I once set up a bench test where I used a heat lamp over a refrigerant charged compressor- the light would warm the compressor and the pressure gage would rise slowly to 400 psi over 3 hrs time. I had a computer linked to a pressure transducer to turn off the light at 400 psi- the unit would then cool and the internal pressure drop to ambient temp and pressure of 80 psi over about 5 hours. Then the computer turned the heat lamp back on . I did this while I was working nearby- I had my leak detector sitting over the top of the compressor- it would trigger at exactly 232 psi on both the upswing and downs wing of pressure cycling-It got so I would anticipate when it neared that pressure- and I'd gather a group to come in and watch "Old Faithful" I let it cycle for two days- automatically going up and then cooling down- again at 232 psi I could hear what sounded like a mouse chirping- it was the o-ring fibulating- squeaking at the rear cylinder to rear head joint of my HT-6 compressor. I let it go on the 3rd night and came in , in the morning and my light bulb was shattered due to the leak actually spraying refrigerant on my hot bulb- glad I was not there.. But goes to show you that leak checking can be a science- only at 232 psi for this unit did it leak- at no other time did my leak checker squeal- from 80 psi to 400- except at 232 psi-- so this is why I am a big dye proponent- dye tells you if and where it leaks- not pressure or time dependent. A leak checker tells you it is not leaking at the present time and pressure- and you can be fooled by a leak checker-

[wptski]

That means leaks can be a PITA?? So what's your method?

Do you know off hand is the HR6 manifold "O" rings are oval? The OEM's look round to me!

I used POE glow oil so it has dye. Since I didn't loosen the accumulator itself to reconnect the low side line, I might have pinched the "O" ring so I checked it. There was was oil inside the fitting so the pressure test moved oil in the system. The only thing with leak dye is that you have to start off clean and you really see can't evey square inch on this compressor unless it runs down where you can.

What about a little R134A and boosting the pressure with nitrogen? I do know using compressed air instead can be dangerous under "certain" conditions.

Probably too wide to wrap around the compressor or have the space for it to fit but I have a refrigerant tank heater blanket, at 125F that would be 183psi.

[GM Tech]

My method is mostly dye- clean off suspected areas with carb cleaner- then let it sit a few days if needed. Note - you can't use a leak detector once you blow carb cleaner - have to wait a day or two..

[wptski]

My method is mostly dye- clean off suspected areas with carb cleaner- then let it sit a few days if needed. Note - you can't use a leak detector once you blow carb cleaner - have to wait a day or two..

I assume a full charge and operating after for leak check?

[wptski]

Before installing the compressor would hold 150psi over night but would lose a few psi at 200psi but I thought, how long or how often with it be 200psi while in use?? I installed it.

It held 100psi but lost a little at 150psi of nitrogen. Using a liquid leak detector, I couldn't find any leaks. I often read here just add a few ounces and use a sniffer. It's cooling off around here now and was in the sixties so static pressure should be in the sixties with R134A. The system holds 44oz and it took 32oz before it reached the static pressure. The POE oil had dye but nothing was seen or found with a sniffer so it was so close to a full charge, it just added the rest.

A/C in max, windows open and vent output was ice cold although I didn't measure the exact temperature. I had cleaned everything with carb cleaner prior a few days ago. Closed the windows, shut it off and waited a while.

Using a sniffer and looking for the dye. Lots of different stuff glows other than the dye itself! I checked inside the vehicle vents, under the dash, around fittings, accumulator and condenser. The compressor due to its location is a bit hard to get all around every square inch of it but I did find a leak at the center body section "O"ring.

Funny just like GM Tech's story above, I detected the leak but when it sat a bit, it couldn't be found till I restarted it again like it leaked at a specific pressure. I'm going to pull the compressor again and do like GM Tech did since I have a manifold adapter, charge it, use a heat lamp and check for leaks.

Not sure if, "The third time is a charm" if I rebuild again or should I just get a replacement??

[wptski]

Here's some highlight excerpts from a unlisted YouTube video I did on testing my HR6. It was charged with refrigerant and heated with a tank heating blanket which is supposed to go to 125F but unsure it did get that high as it cycled frequently.

Leaks came/went as it heated up and cooled down.

https://youtu.be/bq2YUJwzN5g

[wptski]

More confusion! Another short YouTube video of the compressor with 200psi of nitrogen on it showing dye leaks which showed up when submerged in water. Compared to my other video above, leaks show under one condition but not under others!

https://youtu.be/Ex09Qo_lyH4