Replacement for leaking cap on top of jet pump

[BobJackson]

Hello,

Last weekend I noticed that the small plastic piece on top of my jet pump was leaking, after spending the day fixing an ongoing problem with the well. My shallow well is an old piece of garbage that is in dire need of replacement, and currently there are tiny roots that grow out into the water and tangle in the foot valve. I have to cut them back a few times per year, but let it go too long this time and ended up with a barely functioning pump. The first time this happened after we bought the house a couple years ago, the pump completely lost prime and it took me a couple days to figure out the pump wasn't actually dead, and what the real problem was.

This time I went to remove the 3 foot pipe running from the pump down into the well, as I did when the pump "failed" a year and a half ago. I neglected to think about the fact that this time the pump was technically still able to pump, and as soon as I hammered the pipe off water exploded into the pump house. What a way to spend a Saturday evening... I figured that these pumps all had built-in check valves, but obviously not. After cleaning out the well and putting everything back together I noticed this small plastic plug on top of the pump was very slowly leaking. It's right above the pressure gauge and has a flat head slot in it, so I thought is was for adjusting pressure. After looking online I think it's actually a priming plug, but from what I see online those are usually metal and don't look like what I have. I haven't been able to find any info online about this old pump (a Mastercraft 1/3hp jet pump). I never saw a leak at this point up until now, and I'm wondering if the rough-running pump, with air in the lines damaged the piece with the hard pressure fluctuations.

I've included a couple pictures, and I'm wondering anyone can tell me where to go from here. I can't think of a way to cleanly get the water out of the line without making a mess of the pump house again, and I figure if I unscrew whatever this plastic piece is in order to find something with the same thread to replace it, then water will jet up to the ceiling. Last time it at least went sideways and I could direct some down into the well. I must be missing something. There must be a way to evacuate the water lines above the pump before dismantling hoses in the pump house. The lines go up a steep bank about 30-40 feet to the house, so gravity keeps the lines mostly full even if I try to purge the water inside the house with the pump off.

Even if I could empty the water lines easily and take this plastic piece off the pump, I haven't seen a piece like it online. We plan on redoing the entire water system in the next few years, but that requires buying 2 holding tanks (one for the well to replace the crumbling cement/wood basin and one to bury in the yard for our house water holding tank), building a new pump house, running bigger water lines, and redoing the old plumbing in the basement before where the water enters the new UV system. We don't have the money for this now, and I'm trying to limp through with this old pump. If I need to buy a new one now then so be it; they're not that expensive. We plan on going with submersible pumps when we redo the water system so a new pump now would be useless later.

Any info on this pump and what this piece is I'm looking at would be very helpful. I also welcome any tips on avoiding getting soaked trying to remove pipes from the pump. Thank you in advance.

(For the pictures, the rusty paint tray is to catch the drips that always last for a few weeks after playing with the pump. The old socks are to try to catch the water coming from this leaking plastic piece, with a small fan to dry the wood that gets wet. One final thing, after looking at the closeup picture just now, it looks like a chunk has been taken out of the base of the plastic piece. I've never noticed this before because I've had no reason to inspect it, but it almost looks like it's been chewed on. There were mouse traps in there when we bought the place, but nothing was ever caught, and I've never seen any real sign of mice in there)

 

[Valveman]

That looks like the back pressure valve that is needed when using a convertible jet pump as a deep well two pipe system. I don't think is does anything when using the pump as a shallow well pump. It may not be standard pipe thread though. Probably has a gasket or o-ring that needs replacing.

30'-40' of elevation after the pump will drain back a lot of water. Just open a faucet and let it all drain down before taking the pipe apart. If you had a ball valve after the pressure tank closed it would keep the house water from draining back down.

 

[RS]

If you can't isolate line going up hill to the house, is there a place to connect a hose to get rid of the water? That screw in the top of the plug might be to vent the air out when priming the pump. If you break that fitting trying to get it out, and it's not standard pipe threads, you're screwed, you will probably have to replace the pump! So, you might be better off just dealing with a small leak until the system can be updated.

 

[BobJackson]

Thank you for the replies. Yes, I wish I had a valve somewhere in the line between the pump and the house, or anywhere to connect a hose. I thought about adding in some hose tee fitting in the line right above the pump, but the work week was coming up fast and I just wanted the water running again. I should have just made the extra trip to the store though. There are of course shutoffs in the basement before the holding tank in there, but they only stop water from entering the holding tank. If the well pump isn't running, I can open a valve on a sediment filter in the basement and that drains maybe a gallon of water, and the rest stays in the lines. If need be, the next time I'll try to pry the poly pipe off the bottom of the L that directs it down into the well. It's a super awkward angle, but at least that will shoot the water into the well and not straight into the wall.

That piece that's leaking, it isn't coming from the seal against the metal, but from that chunk out of the middle of the flange. The whole piece has very tiny cracks on it, and just looks like old deteriorating plastic. You can't really see it in the picture, but it almost looks like the top is separating from the flange. I'll have to really think about this. The leak is fast enough that I can't leave it alone, but I can't be making trips down there every couple days to change out a towel, climbing through 3 feet of snow. It only took a day for it to soak the wood floor right under the pump, and if it fails the pump house will be soaked and I won't know about for a day probably.

I may just have to take my chances and drain the line and take that piece off, and hope I can find something to screw in there. I'll do some more searching on this model and see if I can find anything specific. If I end up removing that piece I'll post back here with an update in case it helps anyone else.

Thank you again.

 

[Valveman]

It might have a regular pipe thread. But I would order a new replacement part before removing the old one.

 

[BobJackson]

I called to try and find some info on this pump and to my surprise they actually found it in their system. I looked online for over an hour to find any info at all about this model and found absolutely nothing, so I figured it was obsolete (which it probably is) and wouldn't get any support on it. The guy on the phone didn't sound too reassuring, but he did mumble about it being regular pipe thread. He also said the same as you Valveman about that plastic piece being pointless for my use. I didn't doubt you though, he just offered up that info! I just bought a plug to screw into that hole, but if I'm going to temp fate again with potentially flooding the pump house, I'm putting in a splitter and hose hookup on the discharge after the pump is empty. I'll be picking those pieces up soon.