Newly installed jet pump wet end leaks like there's no shaft seal

[DangerBoy]

Hi all,

I just replaced the entire wet end on one of my jet pumps with a brand new off-the-shelf waterways wet end and when I went to start filling the tub, water was just gushing out of the back end of the wet end around the motor shaft. It is as though the wet end came without a shaft seal installed. What is going on?

I am just about to start removing the jet pump out of the tub (I have to get the heater first to make enough room for the jet pump to come out first) so I can investigate the problem. Does it ever occur that those Waterways wet ends are shipped out from the factory defective and missing the shaft seal? The last time I bought a brand new Waterways wet end it was missing a part right from the factory and I had to exchange it for another one so this is why I ask.

I had some troubles getting the impeller to thread far enough on to the motor shaft so that the legs of the wet end would seat onto the front face of the motor so I had to pull the wet end and motor shaft apart a few times to finally get it on all the way. I later found on the ground near where I was working an o-ring with an i.d. that's pretty close to the diameter of the motor shaft. I thought the o-ring was for something else so I just put it aside and continued with re-installing the jet pump. Could that o-ring have been from the wet end and is the reason why the wet end is leaking so badly around the shaft?

I hope someone is able to help soon because it's getting cold here and I need to get that tub filled and running or else I risk freezing it. Thankfully, it never got down to freezing last night.

Edit: I just figured out what might be the problem or part of the problem. The wet end came missing the wear ring on the impeller. That is the second time this has happened. The brand new wet end I bought when I first got the tub was also missing the wear ring. I'm not impressed with Waterways' quality control. Fortunately, I've got the wear ring from the pump I took off that I can use. I see now that the o-ring I found had nothing to do with the issue. The old wear ring is getting kind of powdery so I'll freshen it up with a heat gun.

Could the issue be that I'm not able to screw the impeller far enough onto the motor shaft to compress the spring on the shaft seal?

Edit#2 The pump motor is a 48 frame 1 hp and the wet end is a Waterway 1hp side discharge 1.5" i/o.

 

[ajw22]

Let's see if @1poolman1 has worked on that pump.

 

[DangerBoy]

I've watched a number of videos on how to replace the shaft seals in Waterways wet ends and also replacing wet ends and I believe I'm doing everything correctly. I have tightened the impeller onto the motor shaft as tightly as I can by hand using plyers to stop the exposed part of the shaft from rotating, I put the used wear ring in ahead of the impeller and put it all back together so that's in place now but when I tip the pump almost vertically and pour some water into the wet end, it just runs out through the shaft seal. And it's not just a drip; it just pours right out. I have to believe the shaft seal is faulty/defective. It's not really giving any kind of a seal. What else could be wrong?

 

[RDspaguy]

The impeller is probably not seated. I run the motor with wet-end removed and sand off the shaft. In extreme cases, most of the impeller shaft below the seal can be cut off.
Use of a lubricant or sealant on the shaft threads will prevent full seating due to trapped air.
It is possible, as you've seen, to get faulty parts. Check impeller shaft for debris.
Also, you should install a wet end one piece at a time not as a whole assembly.
I will mention that a new shaft seal will leak slightly until it has been run for a few minutes to smooth the graphite ring.

 

[DangerBoy]

@RDspaguy Thank you very much for your insights and knowledge. I put some of that Molybdenum thread-eze stuff on the shaft threads to prevent the brass impeller threads from seizing onto the steel shaft threads as they always do. Do you think that could be part of the problem? I will wipe it off and try again. I did install the wet end one piece at a time. You have to do that in order to screw the impeller tightly on the motor shaft. I suppose if I disconnect the heater I can power up the 240 circuit to power the pump so I can run the motor and sand the shaft as you suggest. I did sand it a little with the motor not running. If I have to, I will cut off some of the impeller shaft below the seal. Wish me luck.

 

[DangerBoy]

This is the impeller. Notice that the seal is not pushed all the way down so there's about a 1 mm gap between the seal plate and the underside of the impeller? Is it not supposed to be pressed on all the way so there's no gap there? If yes, could this be the reason for the leak around the shaft?

 

[RDspaguy]

put some of that Molybdenum thread-eze stuff on the shaft threads to prevent the brass impeller threads from seizing onto the steel shaft threads as they always do. Do you think that could be part of the problem?

Yes. It traps an air pocket that you can only compress so much.

Is it not supposed to be pressed on all the way so there's no gap

There's an o-ring in there, the plate will eventually be on all the way as it deforms under pressure.

 

[RDspaguy]

I do vaguely recall an instance where I had to put washers between the motor and wet-end, on the 4 thru-bolts, to get a seal. Can't remember the details though, it was a long time ago.
If it still leaks try using the original housing body, if it's not cracked, with the new impeller.

 

[DangerBoy]

Unfortunately, I ended up having to destroy the old wet end body/housing to get the old impeller off of the shaft, despite the clever trick you showed me for making a special tool to stop the impeller from rotating. That impeller was really stuck onto the shaft. It may have been the original wet end so was on there a very long time. The tub will turn 30 years old next year.

 

[DangerBoy]

I tried it with the thread-eze removed and both sets of threads thoroughly cleaned. It did not help. I even tried using a bigger set of plyers on the motor shaft so I could get the impeller on even tighter.AND I tried putting washers in between the legs of the wet end and the motor end but even that did not help in the slightest. Water just pours through the shaft seal. It has to be completely defective in some way. That is the only explanation I can come up with. I never had any of these issues when I put a new wet end on the other jet pump. It sealed and worked perfectly first time.

 

[RDspaguy]

Yeah, I don't know. How fast does it come out? Is it literally pouring?
See if you can compress the spring. Maybe the metal sheath is stuck or something.
Pull the ceramic ring and rubber cup and check for cracks in the wet-end when you push on it.
Might have to get a new one. Bad parts do happen.

 

[DangerBoy]

I sent that one in as defective and got a replacement which also didn't come with a wear ring. It seems that maybe they don't make them with wear rings in them anymore. I had an unused spare one so I put it in anyways.

As per your suggestion, @RDspaguy, I put a couple of small washers between the base of the wet end and the motor and got a good seal on the shaft seal right from the get-go. I tried it at first without any washers and the shaft seal leaked quite badly just like the first wet end I had tried. The first wet end I had didn't seal at the shaft with one set of small washers inserted between the base of the wet end and the motor so with the second wet end I went straight to trying it with two small washers inserted and that worked well. I figured that was good enough so I didn't bother to try with just one set of washers inserted. Maybe the first wet end I got would've also worked with two washers inserted between the base of the wet end and the motor but we'll never know now since that one was returned to the supplier.

At any rate, the problem is solved, the tub is filled and no leaks are coming from either of the jet pumps.

Thanks again for your help @RDspaguy! Your suggestion about inserting the washers between the base of the wet end and the motor was what did the trick.

 

[RDspaguy]

seems that maybe they don't make them with wear rings in them anymore. I had an unused spare one so I put it in anyways.

So, you got a new wet-end without a wear-ring and decided to use parts from the old one in it? Just to be clear, we are talking about a plastic ring on the front of the impeller, right?
Glad it worked, hope it holds.