Ballast Mod Issues - 05 WSLSV

Last year I changed the rear ballast on my 2005 WSLSV. I took the overflow from my rear tanks and ran them to sacs that sit on top of the tanks. The new overflow was run from the sac out the side of the hull.

This system works great and was nice since I didn't have to add any pumps or do any additional wiring. So the idea is that the tanks fill first and then they begin to overlow which runs into the sacs. The sacs are vented by the the new overflow. To drain, the empty pumps empty the tanks first and then gravity empties the sacs back into the tanks.

This system works great with one exception. When the tanks are full and the sacs begin to start filling, the pressure starts pushing some water out the empty line of the tanks. It isn't a ton but I know it definitely slows down my fill times.

So any suggestions on how to keep that from happening? I know others who have done this mod but don't have this issue so I am not sure why it's happening.

Weird. I have the exact boat and the exact ballast set up for my rear tanks, and I don't think I have that problem (or at least I've never noticed).

How much time is it costing you?

You're the one I was talking about David! I tried to get some answers on TMC.com but didn't get anywhere so I was trying my luck here.

I'm not sure how long it is costing me as it has always been this way. I don't have anything to measure it against. Either way though it's faster than manually connecting pumps each time.

So you've never noticed this happening? How long would you say it takes to fill both your tanks and sacs? I have the 400 pounders in the trunks. The only other thing I probably should change would be to put a loop in the sac overflow line. When the sac gets full then the sac exit point is the same height as the thru-hull overflow. Once you put gear on the sacs I lose some water out the sides. How do you manage this?

I was also hoping to do this exact same thing and was wondering which bags you have Eubanks? I have a pair of 600# but both valves are on the top of the sac. I would assume you would need the fill/drain at the bottom and the overflow at the top.

Could your problem be that the force of gravity of the water in the extra sacs being above the water line is causing the water to flow backwards through the forward running pump? It's only a guess but thats what i was worried about with doing it on mine.

David - You are right on the holes and the connections. The Pro-X Series sacs are what I have and they have 2 holes on top and one on the bottom. You can get the quick connects so they sacs can be easily taken out.

I'm not sure what's wrong. It seems to be pushing water past the draining pump...which I didn't think was possible since water couldn't flow thru a pump that was not on. Maybe I am mistaken. I was hoping to find out here but no luck yet!

If it is pushing water past the pump it would probably take a valve on that line to fix it. Why not try teeing the fill line so both the tank and the bag fill at once maybe this will relive some pressure on the tank.

BTW centrifugal(sp) or livewell type pumps will not hold pressure when off.

Are there seperate pumps for fill and drain on Malibu's? I feel bad asking because its my boat and I dont know.

If i have both my fill and vent on the bottom of the sac it should fill from the overflow of the stock but shouldnt it not overflow if the vent for the sac is above the height of the highest point of water? or will the pressure of the squeezing bag force it out the vent?

Eubanks-
I have a 2004 WSLSV, which is a little different from yours. My hard tanks were above the floor in the rear compartments, so I removed them and plumbed in 700 pound sacs using the original factory hoses/pumps. I found that when I first did this that my sacs would empty out the fill and drain lines (water would push past the pumps) and the sac would lose a lot of its water over time. So, I put a cheap one-way check valve in the fill line to keep the water flowing one way. Since this same thing wouldn't work on the drain line, I had to buy some expensive electonically-activated valves for these 2 lines. I found some from stcvalve.com for $62 each. I spliced them into the drain pump wires so they activate when I hit the drain switch. Now the sacs stay full, and it was overall a pretty easy fix.