Sabreline water leak problem

The fresh water pump runs often without the use of water. I can't find the leak after looking at all possible location, engine room, under the sink, water pump and accumulate tank. The bilge pump comes on often is this a coincidences.
Anything on the leak or bilge pump.
I have a Sabreline 1992, DD8.2L, 36', aft cabin trawler with 1400 hours.

What kind of bilge pump? Where is it? And does it come on immediately when the fresh water pump does? Does it pump any water signifying it is pumping leaked water or is it just possibly just coming on from vibration of the fresh water pump?

I believe on some fresh water pumps, internal to the pump end, the valving experiences leakback and thus the pressure drops but no water escapes.

That issue would not explain the bilge pump unless it is just vibration or electrical surge if the bilge pump is a computerized one.

Look anywhere there's a connection, hose to fitting (water heater?, etc.).... or anywhere a hose may have begun to split...


Bilge pump running may not be coincidental...


-Chris

is the level of your water tank going down? for the bilge pump to turn on and off auto matically, unless computerized.....usually the amount needed to do that is more than a tiny leak unless measured over days.

Does the bilge pump send water overboard when it kicks on? Fresh or salt?

Sleuthing required by eyes, hands, towels and ears onboard. If FW pump equipped with check valve insure that is not back flowing into tank. Good luck.

Buy some food dye from the local supermarket (used for cake frosting etc.) and put it into the water tank. Then look in the bilge compartments for colored water to help locate a leak.

Some bilge pumps run every few minutes for a few seconds. If they feel no resistance (i.e. no water is being pumped) they turn off.

Did you check the water heater connections?

Have you done a pressure test to see if it is holding pressure. It is simple to do. Run the pump until it shuts off without any taps open. Turn the pump off then run water into a stoppered sink to see how much you get. Turn the pump back on until it shuts off, turn the pump off, wait several hours then run water into the same stoppered sink. If the volume is less than what you got the first time you have a pressure leak somewhere. It could be a fitting or as mentioned above, a poor valve in the pump that lets pressure bleed off internally.

A quick solution is to turn the pump off when you are not using it.

We are going to replace the pump because there is not any evidence of any fixtures, hot water tank, or hoses leaking.
Best guess is the check vavle allows water to go into the water tank.

Great suggestions and help. There is not a drop of water anywhere so food coloring or rags won't do the trick. I don't know if it is salt or fresh water in the bilge. I thought of collecting a small amount of water from the bilge and letting it evaporate on a plate or other surface and see if there is a salt residue.
I will let you know about the solution. Thanks

Great idea to turn off the switch at least at night so the pump doesn't run waking us up.

Try some non toxic vegetable dye in your water and see if that helps trace a leak.

What has yet to be mentioned is the possibility that your accumulator tank has become "waterlogged" this will cause the cycling of the water pump. The tank should have an air bladder that maintains the tank at about half full of air. If the air is missing the pump will turn off and on very often.
If you go with a dye as suggested in several posts above, might I suggest a swimming pool leak detection dye rather than the food dyes mentioned. It would take less dye and less $.

From my similar Rv experience a little food dye in the tank will allow you to trace it down. Mine was a pin hole in the heat exchanger/tank on the hot water heater.
Pimp cycled 1 or two times per hour and after a couple of days of looking in all the hidden spaces under cabinets and under slide outs it showed up on the outside of the coach, under the water heater vent.
Also had a friend that had a micro crack in a 1/4 " ice maker feed line. That also revealed itself on the outside of the coach.
Good luck.

"I thought of collecting a small amount of water from the bilge and letting it evaporate on a plate or other surface and see if there is a salt residue. "

Taste the water and you can quickly tell if it is fresh or salt water.

Solved

TT54 said:

The fresh water pump runs often without the use of water. I can't find the leak after looking at all possible location, engine room, under the sink, water pump and accumulate tank. The bilge pump comes on often is this a coincidences.
Anything on the leak or bilge pump.
I have a Sabreline 1992, DD8.2L, 36', aft cabin trawler with 1400 hours.

Click to expand...

Thank you all for your replies to my question we now shut the pump off at night and when we run during the day there isn't any more problem with the pump.

drb1025 said:

"I thought of collecting a small amount of water from the bilge and letting it evaporate on a plate or other surface and see if there is a salt residue. "

Taste the water and you can quickly tell if it is fresh or salt water.

Click to expand...

Be careful with that taste test, I had just a small clear puddle in the normally bone dry bilge,
I did the taste for salt water or fresh test a couple of drops on my finger
neither, but battery electrolite from 2 8Ds that had boiled over from a charger gone bad. Got a blister on my lip and burned tounge. Before that there was the time it was the shower sump had overflowed, no blisters but the thought of tasting old shower water, yuk!

Once our water pump was cycling on more often than usual, and there was some water in the bilge it was from a sink fitting that was leaking.

With their different densities there must be some things that would float in a cup of saltwater, but not fresh. May be a safer alternative to tasting. And if you do it in say a solo cup, if it's battery acid, you'll know that also.

No Mast: Good thought but the difference between the densities of the salt / fresh water is only about 27 kg/m3. If you truly want to find out if it is fresh or salt water there is a simple test for that without involving your tongue or lips. Take a sample of the bilge water hopefully clean or clear and a sample of fresh water. Put food coloring of one color say red in the bilge water sample and one color say blue in the known fresh water sample. Pour both slowly into a clean jar if you see two colors then they are different densities. If they blend they are both fresh water.

ulysses - I may try that just to check it out and see it working!

Or just use your hydrometer if you do not wish to mess with all the food coloring.

TT54 said:

The fresh water pump runs often without the use of water. I can't find the leak after looking at all possible location, engine room, under the sink, water pump and accumulate tank. The bilge pump comes on often is this a coincidences.
Anything on the leak or bilge pump.
I have a Sabreline 1992, DD8.2L, 36', aft cabin trawler with 1400 hours.

Click to expand...

We have a 94 Sabreline aft cabin trawler. I have an AquaJet water pressure pump by Johnson which is designed to work without an accumulator tank. I have noticed the same issue of the freshwater pump running when the galley faucet drips even a drop or 2 a minute. But I also notice that the "on" tank level drops even between visits to the boat. this happens whether the stb, mid or port tank is selected. How fast are your tank levels dropping? I do not have the bilge pump running situation so I know that only a small amount is leaving the system. Like you, I have been unable to find any leaking at any joint or fitting that I can see. I suspect that it is a water tank fitting but haven't gotten at them yet--you know the tanks are built in under the master bunk. and a pain to get to. Let me know what you find out.

ulysses said:

Or just use your hydrometer if you do not wish to mess with all the food coloring.

Click to expand...

Probably not enough liquid to float the hydromerter bulb or beads.

Why not sprinkle a bit of soda (from the fridge) in it. If it fizzes it's acid...