Backwash through bilge pumps???-gctid343913

[Guest]

If this has previously been discussed I am sorry. We are presently on the Great Loop in a 2000 3988. Many people have commented how low to the waterline the outlet holes are for everything on this model. We normally have a dry boat under regular conditions but I have been collecting a little seawater around the midship pumps any time we run in heavy seas. I have a feeling it is caused by seas hitting on those holes and pushing seawater up and over the highest point in the hose causingit to spill out of the pumps as backflow. If it gets too deep I am sure the pumps would push out as much as they could but I never see the lights come on while running to indicate this has happened so it is not that much coming in. Has anyone else dealt with this? It is more a bother than anything else because I have to wet vac it out(less than two gallons) and seawater creates more odor potential in bilge than fresh.

[iceclimber]

No need to apologize. My boat is considerable older and most likely more porous than yours and it does exactly the same thing. It can stay reasonably dry forever and then suddenly I have a couple gallons down there. I have found inner peace and accept it. I also got a long extension for my shop vac hose.

[Guest]

TheJudge wrote:
seas hitting on those holes and pushing seawater up and over the highest point in the hose

The highest point of the anti-siphon loop is quite high, and would require sustained pressure to fill it. I'd be surprised if this were your cause. Unfortunately, the only way to rule it out might be to have someone lay there with a flashlight, running in the right conditions, and monitor it.

[mmichellich]

Do the bilge pump lines contain check valves? Most Bayliner bilge pump lines do not go high enough to prevent this issue in rough seas.

[Guest]

mmichellich wrote:
Do the bilge pump lines contain check valves? Most Bayliner bilge pump lines do not go high enough to prevent this issue in rough seas.

Most bilge pump discharge lines don't have check valves.

[Guest]

Hello would a non spring, lift or swing check valve prevent this? Our 4588 did not have them but we were advised to use them when we rebuilt.

Cheers steve

[mmichellich]

whiskywizard wrote:
Most bilge pump discharge lines don't have check valves.

Of course they don't but that does not stop a whole lot of owners from adding them to stop the problem identified. I know at least 5, 37 and 39 owners that have added check valves. One 37 owner had the issue with just a couple of folks in the cockpit both on the same side of the boat-and Bayliner installed them to fix the issue under warranty. The thru hulls are just too close to the water line.

[SomeSailor]

I would also look at the possibility that the through hull is leaking at the hull. Adding a bit more service loop above the waterline would rule out the bilge pump backwash. Also, don't forget to check for a freshwater leak. I have a small freshwater leak on mine right now that I need to chase down. It only takes a drip to add up to gallons in short order.

[Machog]

Also check if it could be rain water?

I get water in my aft bilge, but its fresh, not coming from the water or holding tank, but when it rains it starts to fill.

Recommend you check by smell not taste-you never know what route the water took to get there!

Machog

[Guest]

Check valves are not recommended in bilge pump discharge lines as they may foul and block flow when you need it most. While many loops are installed at 12", if you hare having trouble inceasing to say 18" may help. Most Bayliner Motoryachts have a series of overboard discharge fittings installed in rows - sometimes one or two of these are not used, and are just left open - bad news - if you have any of these, cap them off! Plenty of advice here: http://www.yachtsurvey.com/bilge_pumps.htm. ABYC standards generally prohibit use of check valves in bilge pump discharge lines. Good luck, Doug S.

[SomeSailor]

Machog wrote:
Recommend you check by smell not taste-you never know what route the water took to get there!

Machog

Or a $10 aquarium salinity kit.

[seaclusion]

do a dye test on your fresh water tank .......a simple idea is couple of bottels of food color in the tank will work to find out if tanks leakes or not

[Guest]

As I touched the salty wet finger to my tongue I instantly thought this was not a good idea but this was some time ago and no ill effects thank goodness. So it is not freshwater. I am convinced it is those bilge pumps because it only occurs in strong seas. When we are on the Tennessee River there is no trouble but run an hour or so getting tossed around in a beam sea and we are wet. I too would not put check valves in a bilge pump hose but agree a higher loop in hose would be a simple modification with no downside.

[Guest]

I ran into this several years ago on a small cabin cruiser and was able to see it while it happened. I would check how high up the bilge hose loops above the thru-hull. If I'm not mistaken it should be at least 18" per ABYC standard.

[hargsnz]

I have had similar problems on my 32ft. Just in rough seas.

I narrowed it down, I think, to water entering through the anchor chain fitting on the bow.

No other sensible other explantation after looking at every thru-hull fitting.

It's the rough seas over the bow - but it takes a while to get through the length of the boat to, on my boat, the front bilge, so it's hard to relate the two - but it's the only explanation I have for salt water in there.