vacuum leaks

[ollieman]

I'm going to vacuum this year and I'm in the process of hooking up the pump,moisture trap and re-leaser. Today was the first time starting the pump so I wanted to check system for leaks I have a ball valve between the releaser and moisture trap which I shut off so I could test the moisture trap to the pump. Started the pump and it pulled 26hg but when I shut it off it started losing vacuum. I can hear it but can't located leak, what can I do to locate leak on vacuum, if it was pressure I know water or liquid soap. Also there are no lines attached yet, only plumbing on pump and releaser

[unc23win]

I'm not sure if I'm missing something or not. If you shut the pump off the vacuum should leak from the releaser slowly. Assuming you have a mechanical releaser that is the flapper will only be fully sealed under vacuum. This allows for sap that runs without vacuum to drain out the releaser. With limited amount of fittings you have you should be able to feel around joints and then hear the change in sound at the leak. If you run constant 26" under vacuum I think your fine a leak would be very loud under that much vacuum and with nothing other than the pump, releaser, and trap plumbed.

[OGDENS SUGAR BUSH]

your pump will lose vac as soon as you shut it off,

[spud]

A few years ago my vacuum pump was running 29 inches at the pump but only 27 at the releaser just 20 feet away. I checked all the fittings in between and even replaced some but still there was a lose. I then replaced the sleeve that connects the releaser to the vacuum line because I noticed the two black O rings were wearing. I also sprayed every fitting seam from pump to releaser ( but not the sleeve) with Flex Seal and now I have 29 at the releaser. The flapper on the moisture trap will leak vacuum once the pump is off. This is normal.

Spud

[Haynes Forest Products]

You will get back flow thru the pump and that is normal That is why you should also have a check valve in your system between the woods and the pump. Once your entire system is up and running and it shuts off you can get back spin if its a vane pump. Plus many pump seals only work when there is good constant vacuum or pressure depending on the style of pump. Many vane pumps dont have mecanical seals at all and depend on CFM's to compinsate for the loss.

[ollieman]

Thanks for the info but we found the leaks with a spray bottle of water. Both the moisture trap and releaser both have fittings from the factory that are leaking, Now to figure out how to get them seal. They are glue joints with pvc glue.

[unc23win]

Now it is leaking under vacuum? Are they suppose to be glued? My moisture trap and releaser aren't glued sometimes you have to take them apart. Sometimes they just need better alignment.

[Haynes Forest Products]

ollieman Not knowing what releaser you have on a Bernard many of the PVC fittings are machined with O rings. You can use food grade grease that will help leaks. The ones that are glued can have a glue applied when under vacuum to suck the glue into the joint. Now I highly doubt that a glued joint is leaking so check it because most releasers can be disassembled at the fittings.

[wiam]

Is this releaser new or used. I have a Lapierre single vertical that leaked all around the bottom glue joint. This was close to 10 years old. I turned it upside down and used primer and gray cement all around the seem. Guy I buy sap from has same spot leaking on his.