Help with my YJ 69075

[kpsheets0580]

A couple of weeks ago I decided to start getting stuff ready for the cooling season. I wanted to test my micron gauge so I would know that it was in top working condition. I connected it straight the the vacuum pump and let it run for awhile. I then isolated the gauge from the pump to see what would happen. The reading kept going up and up. After trying several different things I felt that it was the brass coupling that was causing my readings to go up. Instead of just replacing the rubber seals I bought a new coupling. I tried the test again and got the same results. We had a brand new sensor at the shop so I decided to replace my sensor with it and still got the same results. Just to make sure that the fitting on the vacuum pump wasn't leaking I put my YJ schrader core removal tool between the gauge and the pump. Still same results. Here are some pictures of the set up I was trying and the micron readings I was getting. Does anyone have any ideas as to what is happening?


Heres the set up.

http://i175.photobucket.com/albums/w157/kpsheets0580/DSC02102.jpg

Pulled down to 16 microns.

http://i175.photobucket.com/albums/w157/kpsheets0580/DSC02101.jpg

Closed the valve on the 4 in 1 ball valve and after 5 minutes.

http://i175.photobucket.com/albums/w157/kpsheets0580/DSC02105.jpg


After 10 minutes.

http://i175.photobucket.com/albums/w157/kpsheets0580/DSC02106.jpg


After 15 minutes.

http://i175.photobucket.com/albums/w157/kpsheets0580/DSC02107.jpg

After 1 hour.

http://i175.photobucket.com/albums/w157/kpsheets0580/DSC02108.jpg

[Senior Tech]

The easy answer is you have a leak somewhere...did you try another micron gauge with the setup you used?

[kpsheets0580]

Yes I did and it never went above 100 microns. Thats whats got me so baffled. I even put in a new battery.

[Senior Tech]

Possible internal leak within micron gauge...I would send it in to yellow jacket.

[toy501]

Don't ask me why but i was told that it's not a accurate test when u put the micron gauge straight to the vacuum pump. Try evacuating a empty recovery cylnder and put vacuum gauge to the other port of the recovery tank and see what u get.

[rojacman]

Yes I did and it never went above 100 microns. Thats whats got me so baffled. I even put in a new battery. I would put a 1/4 flare union in the female connection at the ball valve and pressurize with 1/2 psi pos. press & leak ckeck the entire ass'y. (if your guage mfr will allow pos press on the sensor). If you can use 10 psi you'll find it easily. good luck Jack

[clothe]

Dear Sir, I'm Having The Same Problem With My Yjvg. I Did The Same Tests You Did And Got The Same Results. What In The World Is Going On.. What Can Be Causing This Problem? Is It Electrical? Is There A Leak Some Where. This Is Sure A Mystery That Needs To Be Solve. Our Hvac License Depends On It. Joking.


Frank

[dennyf]

Sorry to resurrect this thread from the dead, but I'm having the same problem with my YJ 69086. Did you guys finally figure out what was causing the micron reading to go up?

[jtrouse]

Other things to consider:
Contaminates in the evac sensor can give these increases but if you can get 16 microns with the pump running, contaminants in the sensor is most likely not the problem.

Excess (and not so evac clean) oil in the closed off area will give this kind of increase.

This below will probably do it if you don't have any real leaks:
Try closing and opening the add-on ball valve several times at 16-25 microns with the pump running. Then close off the add-on ball valve (with the pump still running) and then, slowly, barely open the ball valve just enough to halt the micron increase. Then let the pump continue to run and the micron level will slowly decrease again with the add-on valve left barely open. When the level gets back down to 16 as shown in first pic, close the add-on valve off and the level will climb a lot less and a lot slower (if there are no leaks) even with the pump turned off.

The reason for the open/close routine at a low vac, with the pump running, is to clean out most of the "back side places" of the ball valve that are pretty much isolated from the regular evac flow when the valve is left fully open.

The reason for the evac with the add-on valve barely cracked open is to get most of the remaining contaminants (the kind that boil off slowly) out of the "back side of the ball". The close/open routine speeds up the next step and brings more inner valve contaminates up so the evac can remove it during the second part.

These hard to reach contaminates will show up easily when you have a small volume in the test area. If you do the blank off test hooked up to a much larger test volume area, the very small amount of contaminates trapped in the add-on ball valve will be less noticed.

All this is just to test this part of the evac rig. Don't bother with all this routine once you are on the job, just every once and awhile test and clean up one part of your evac set up.

[ryand]

Mine does the same thing and it really pisses me off. I also have tried isolating it and the same results WTF!:deadhorse: The reason im so frustrated is I spent money on a new sensor not to mention this is one of the most expensive micron gauges.

I sure hope someone knows the fix for this:anyone:

[dennyf]

Thanks for the ideas on how to test it. By the way my YJ vac gauge has yet to be put on a system; I just wanted to test it to see how my vacuum pump was doing. What I did last night was hook the pump to my brand new YJ 41 manifold then with a straight through fitting, I connected the YJ Vac gauge to the low side hose. That way I could isolate the vacuum pump with the manifold valve. I kind of did what you talked about (opening and closing the valve; slightly cracking it etc.). Didn't seem to make any difference; when I close the manifold valve the microns start going up (takes 3 minutes to go from 80 microns to 1200 microns). I tried taping all the joints with electrical tape (including the electrical connector to the sensor); no luck. I think I'll send a email to YJ and see if they respond.

[joemach]

Please let us know what you hear back from YJ. I have been quite uphappy with the results on older systems.

I am sure that it has more do do with oil or contaminates than it does a leak.

[jtrouse]

Thanks for the ideas on how to test it. By the way my YJ vac gauge has yet to be put on a system; I just wanted to test it to see how my vacuum pump was doing. What I did last night was hook the pump to my brand new YJ 41 manifold then with a straight through fitting, I connected the YJ Vac gauge to the low side hose. That way I could isolate the vacuum pump with the manifold valve. I kind of did what you talked about (opening and closing the valve; slightly cracking it etc.). Didn't seem to make any difference; when I close the manifold valve the microns start going up (takes 3 minutes to go from 80 microns to 1200 microns). I tried taping all the joints with electrical tape (including the electrical connector to the sensor); no luck. I think I'll send a email to YJ and see if they respond.


My post was based on the set up as shown in the first pic in the first post of this thread. Trying to hold a vacuum any lower than 1500 microns using non-metal hoses is a waste of time. Please notice I said "hold a vacuum", not pull a vacuum. Also new untested equipment is very prone to contaminates and leaks. jt

[brjones]

Taping the joints is a waste of time. It won't hold.

In my experience when I have this problem I have a leak and it has never been the micron sensor.

I use a YJ 93860 dual ball vl evac manifold. Just recently I had this problem and it was driving me nuts. I was using a 3/8" SS hose to the charging manifold and had 3 more 1/4"SS hoses connected with the micron sensor on one of them. I was just checking my set-up to be sure it was tight and clean.

It would not hold. I checked and rechecked connections and replaced all of the Orings. Same result. It was driving me nuts because I needed to use it the next day. I tried adding more vl's so I could isolate different sections, same result. I started suspecting all sorts of things including a cracked SS hose or manifold vl packings etc. But none of my testing made would pinpoint the problem so I gave up.

The next day when I had a fresh start it dawned on me to use N2 and check for the leak using Snoop and presto! The evac manifold has several threaded connections that are factory sealed with some type of Loctite or thread sealer. The top threaded connection on the evac manifold had a pin hole leak!

I didn't want to even try and take it apart and reseal it so I put a slight vacuum on it and used a drop of super glue. I only left the vacuum on it for a couple seconds and then let it cure. Presto!

In hind sight I really took the long road to finding the problem. If it happens again I will move on to a pressure test a lot sooner.

Now with all of the hoses and charging manifold connected it will hold < 35 microns overnight!

Jt is exactly right about the ball vl's. When pulling on a small volume such as just the hoses when you first close the ball vl on the evac manifold it will have a drastic effect. I always close and open them several times before leaving them closed for the actual test. After the 3rd or 4th time the effect is gone.

The odds of the micron sensor being the source of the leak are very small.

[mcewans]

The reason why you get such a fast rise in microns is that there is not enough space to pull a vacuum and hold it. Hooking up the micron gauge directly to the pump is fine for determing if you get a low enough vacuum, but a better way to check the performance of your vacuum pump would be to pull a vacuum on an empty recovery tank to see if it holds. I ususally aim for less than 100 microns. It takes a few hours, but to me its a more realistic way of checking the operation of the pump.

[ryand]

Do you use rubbing alcohol to clean sensor???

[brjones]

Yes if needed but if I am careful it is rarely needed.