Newport Pump Losing Prime?

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russp
Posts: 189
Joined: Fri Apr 01, 2011 5:31 am
Location: Paynesville, Australia

Newport Pump Losing Prime?

Post by russp »

Hi All, wondering if anyone has experienced this problem or has any ideas. We have a std Wilcox Crittenden Newport 1600 which has gone through all the usual calcium buildup, stinky hoses, leaking joker valve, etc and all have been replaced and everything has worked fine for a couple of years, we now leave with fresh water from shower at end of every day and leave through hull raw water supply open all the time.

Just recently the pump failed to prime with flushing sea water even though it is below sea level (I think) but has a small above waterlevel loop on inlet between through hull and pump inlet. After screaming for about 2 minutes on and off and me worrying about drying out and destroying the impeller, it started pumping fine and ran the entire day with no further problem. Came back 2 days later and had lost prime again, eventually started to pump.......

So last week I pulled the inlet pump impeller out and checked all parts, everything seemed fine but I replaced the seals either side and the impeller, reassembled, crossed my fingers and voila, water instantaneously, so went to bed happy.

Two days later tried to run head, no flushing water! After about 2 minutes sucking it started pumping and pumped all day, so:
* Through hull and inlet hose must be clear as no problem once starts to pump
* Impeller and seals are new so can't be the problem
* Everything including bilge is bone dry so no apparent leaks from anywhere

At wits end, happy to hear any ideas.

Russ Peel
Avalon #150
Russ Peel
Avalon #150
KevinMc
Posts: 85
Joined: Sun Sep 08, 2013 5:36 am

Re: Newport Pump Losing Prime?

Post by KevinMc »

Russ, did you even find out the problem?

We took ownership in November and we have the same problem. Toilet flushes fine - but doesn't bring water into the bowl. PO had the problem for years and they just used a few cups of water from the sink to flush so we knew of the problem before purchase. As spring approaches getting the head working right is my next project. So far I haven't checked anything on the toilet. I was thinking the issue on my toilet is either the impeller or the vented loop sticking open. I also have a second supply line (see my earlier post) connected to a Y-valve right before the vented loop. NO idea where that supply line is coming from - fresh water???

So any ideas you have before I start would be appreciated.
Kevin
#59
NavSta Norfolk Marina
pdenoncourt
Posts: 36
Joined: Wed Nov 02, 2005 7:33 pm
Location: Jacksonville, FL

Re: Newport Pump Losing Prime?

Post by pdenoncourt »

Vented loop should not be on the suction side of pump. Normally it should be between the pump exit and bowl inlet. If it is in the suction side, I would highly suspect that is the source of your problem. The vent's function is to let air in so the hose can drain, thus preventing a siphon from developing from seawater to toilet. If it is on the suction side, it will let air in as you are pumping, making it more difficult to get water to the pump. If it were on the pressure side, the flow of water closes the vent valve while pumping, preventing the escape of water, but as soon as the pump stops, the vent will let air in as the hose begins to drain, preventing a siphon to the toilet bowl.

Good luck. I hate messing with toilet pumps, and long ago replaced my Newport with a PhII manual toilet. Much happier now.

Peter Denoncourt
Kite, Hull #72
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russp
Posts: 189
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Location: Paynesville, Australia

Re: Newport Pump Losing Prime?

Post by russp »

Hi Kevin and Peter,

Vented loop should/must definitely be on the discharge side of the pump, on the way to the top of the bowl, surely no-one would install it on the pump suction.

Your problem Kevin could be as simple as failed raw water impeller, in which case not that bad a job to replace if you have the Newport Maintenance Kit. The impeller is quite amazing, it has a series of roller bearings on the inner face and they lock in one direction and freewheel in the other. The motor can rotate in both directions (hence the two position switch, up or down). This means however that it must be installed in the right direction, it has an arrow and the kit shows which way, it should spin in the up position and freewheel in the down position. The "chopper" impeller spins both ways, it is rigidly locked to the shaft.

I think (90&+) now that my problem may be the shaft seal between the chopper cavity and the raw water pump cavity is installed the wrong way around. I assumed both seals should face inwards like on a normal pump to stop liquid in the pump cavity getting out, but in this case I think that if it doesn't prime quickly the bowl empties, there is air on the chopper side of the seal, a vacuum in the raw water pump cavity and hence air sucks through the seal and prevents the pump priming. Last two times I have tried (i.e. not conclusive yet), I have filled the bowl pretty much full with shower water, and the pump has primed and pumped OK, previously I was allowing the bowl to empty and just holding the switch on waiting for raw water in. I suspect this seal should be inserted with the flat face inwards, open face into the chopper cavity.

Hope this helps a bit, good luck with the pulling apart. It isn't that bad, I have done twice now, the only nuisance (at least on mine) is that there isn't enough room behind the motor to withdraw it from the housing, you have to move the whole toilet base to make room.
Russ Peel
Avalon #150
leigh weiss
Posts: 208
Joined: Mon Mar 05, 2012 7:32 pm

Re: Newport Pump Losing Prime?

Post by leigh weiss »

FWIW
My Newport head did the same thing so I removed the pump and used a rebuild kit to fix it. About $110 on line.
I discovered that the water impeller has a built in one way clutch allowing the impeller to free wheel (not pump) with one shaft direction of rotation and it will rotate (pump) with the reverse shaft rotation. I also replaced the shaft seals and gaskets before reassembling. All went well and the head is back to normal.
Remember the foot switch reverses direction of the motor to give the two functions (fill bowl and dry bowl)
I tried to soak and clean the impeller clutch (do not use oil), but it would not work properly. It would free wheel in both directions hence no seawater to fill the bowl.
Mine lasted about 10 years so I can't complain.
Let us know how you make out with your unit.
Leigh and Donna Weiss
Brisa #155
Georgetown, MD. USA
KevinMc
Posts: 85
Joined: Sun Sep 08, 2013 5:36 am

Re: Newport Pump Losing Prime?

Post by KevinMc »

I don't know how long it's been since sea water actually made it from the thur-hull to the bowl so I'm going to check two areas; the pump and impellers and the lines themselves. I believe the way it's on my boat is the raw water line running from the thur-hull to a vented loop then to the pump.

I'm reading the proper set up is -
1) Line from the thru-hull directly to the pump
2) Line from pump to a vented loop then back down to the bowl
3) Discharge line from the bowl to the holding tank
Kevin
#59
NavSta Norfolk Marina
leigh weiss
Posts: 208
Joined: Mon Mar 05, 2012 7:32 pm

Re: Newport Pump Losing Prime?

Post by leigh weiss »

Kevin,
Be sure to check that the correct hose is connected to the pump. The suction side of the pump must go to the raw water input and the pressure ( discharge ) side goes to the vented loop. The hoses are the same size and may have been switched.
Leigh and Donna Weiss
Brisa #155
Georgetown, MD. USA
KevinMc
Posts: 85
Joined: Sun Sep 08, 2013 5:36 am

Re: Newport Pump Losing Prime?

Post by KevinMc »

Water flows!! I will now consider myself knowledgeable on the inner workings of the C-350 toilet. The problem was the impeller. Since I had a replacement Newport toilet as part of the purchase I had the replacement part on hand and installed it today. Talk about a lot of crud getting cleaned off the inside of the raw water intake lines!!

Everyone's comments are appreciated and made the job quicker and smoother (I would say easier by nothing involving boat repairs are easy!).
Kevin
#59
NavSta Norfolk Marina
User avatar
russp
Posts: 189
Joined: Fri Apr 01, 2011 5:31 am
Location: Paynesville, Australia

Re: Newport Pump Losing Prime?

Post by russp »

Congratulations Kevin. Would be nice to have a head that just worked as it was supposed to. I am back to square one, I do have a sound impeller but still don't get priming of the pump and it won't stay primed for more than 12 hours or so once it does finally prime. About to pull all hoses apart, no hair left to pull out!

Russ Peel
Avalon #150 :(
Russ Peel
Avalon #150
leigh weiss
Posts: 208
Joined: Mon Mar 05, 2012 7:32 pm

Re: Newport Pump Losing Prime?

Post by leigh weiss »

Russ,
You might want to check all the hose connections on the raw water side as well as replace the seals in the pump. I found them as part number TCM #03072SC-BX at a bearing and seal store.Much cheaper than finding them at a Marine store.
Look closely at the shaft to make sure the seals have not worn a groove in the surface.
If they have, you might want to replace the shaft as the new seals will not seal for long!!!
Good luck on your quest for a smooth running head.
Leigh and Donna Weiss
Brisa #155
Georgetown, MD. USA
User avatar
russp
Posts: 189
Joined: Fri Apr 01, 2011 5:31 am
Location: Paynesville, Australia

Re: Newport Pump Losing Prime?

Post by russp »

:P :P :P Don't let grease near your Newport Toilet impeller! I posted a query a while back about anyone else having problems with flushing water pumping to the head. I have finally pinned the problem down and it was because I was diligent/stupid and put grease on the shaft before I pushed on the raw water impeller. "IF" I had been using my brain I would have worked out that those tiny roller bearings inside the bush face weren't going to do their job if they were bound up with grease.
Now dismantled, cleaned up with kero then detergent, and reassembled, all is rosey again.

Thanks to all those who offered advice on the matter.

Russ Peel
Avalon #150
Russ Peel
Avalon #150
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