Texas Fishing Forum

Livewell pump air locking

Posted By: Droyhef

Livewell pump air locking - 05/23/21 05:02 AM

Title says it, livewell pump airlocks under way. How do i fix it?
Posted By: Flippin-Out

Re: Livewell pump air locking - 05/23/21 05:23 AM

Are you saying they stop pumping water when you get underway, or after you stop and try to run them again? You didn't say if this was the fill pumps or recirculate pumps, and when you are trying to run them. "Fill pumps" that bring in lake water don't work when underway.
Posted By: Droyhef

Re: Livewell pump air locking - 05/23/21 12:27 PM

Fill pump stops flowing water if motor is in gear. New pump. Usually will not start again without turn off and on several times and letting it sit.
Posted By: Flippin-Out

Re: Livewell pump air locking - 05/23/21 12:37 PM

The inlet for the fill pump is on the transom. When you put the boat in gear to move forward, the transom begins to not have water available for that inlet. The fill pump is not expected to work at any time except when the boat is floating and not underway. By attempting to run it when it isn't going to work, you're sucking air into the system and creating a bubble even bigger than if the pump plumbing simply drained.

When you're going to be underway, the boat manufacturer expects you to turn off the fill pump and instead use the recirculating pump. You need to read the boat owner's manual. From your description, your problem appears to be operator error and unrealistic expectation, not an equipment malfunction. There are some saltwater boats that have a scoop mechanism to get seawater when the boat is underway, but I've never seen this as a factory feature on a bass boat. Such a mechanism would have considerable issues with vegetation clogging in freshwater environments.
Posted By: Stump jumper

Re: Livewell pump air locking - 05/23/21 04:55 PM

With my Ranger there were times I had to put it in reverse to clear an air block. Not an issue on the Champ. The pickup is on the bottom of the hull but I don't normally run the inlet pump when the boat is moving.
Posted By: Droyhef

Re: Livewell pump air locking - 05/23/21 08:15 PM

Originally Posted by Flippin-Out
The inlet for the fill pump is on the transom. When you put the boat in gear to move forward, the transom begins to not have water available for that inlet. The fill pump is not expected to work at any time except when the boat is floating and not underway. By attempting to run it when it isn't going to work, you're sucking air into the system and creating a bubble even bigger than if the pump plumbing simply drained.

When you're going to be underway, the boat manufacturer expects you to turn off the fill pump and instead use the recirculating pump. You need to read the boat owner's manual. From your description, your problem appears to be operator error and unrealistic expectation, not an equipment malfunction. There are some saltwater boats that have a scoop mechanism to get seawater when the boat is underway, but I've never seen this as a factory feature on a bass boat. Such a mechanism would have considerable issues with vegetation clogging in freshwater environments.


Its not a bass boat.

There isnt a recirc pump, it has a gravity oveflow drain above the waterline, its a one pump setup. It worked before at idle speeds, now it doesnt.

I dont need to read the manual thanks anyway, save that remark. I do all my own work.

Its getting air in it that wont get out even with the boat is stopped. It doesnt work even at low idle, I know it doesn't work on plane never expected it too.The pump works once and a while, off and on sometimes gets it going. I pulled the hose and made sure it actually is pumping works fine with the hose off.
Posted By: Flippin-Out

Re: Livewell pump air locking - 05/23/21 08:22 PM

Describing exactly what you have when submitting an issue for assistance will work a lot better. Did you change the mounting angle of the pump when you replaced it? They are often placed at a specific angle or have plumbing done in a particular way so as to avoid trapping an air bubble.

Also to be considered is that the impeller of the new pump is not worn like the one you removed. This means that it will not "leak" (air or water) as readily when at rest. Where your old pump may have bled off the bubble more easily, a tighter impeller seal with a new pump may hold onto air that gets into the system more readily.
Posted By: Droyhef

Re: Livewell pump air locking - 05/24/21 01:51 AM

No changes to angles of hoses or pump mounting location. Impellers on these type of pumps dont work that way, they will work like a piece of pipe if the inmpeller is stuck or when it isnt turning, water or air will flow freely past them if pressure is lower downstream of the discharge. They dont have a seal that only lets water or air by when they are working. I pulled the hose while on the water to make sure there wasn't an obstruction, plenty of water flows by from just being under the water line. When a centrifugal pump gets air in the impeller it doesnt have the ability to clear the air pocket because they cant pump air. What im asking is what to do about it getting air in it in the first place, and i dont think its unreasonable to expect it to work at 2 mph idle speed. Maybe it is but it definitely shouldnt stay air locked after stoping.
Posted By: Flippin-Out

Re: Livewell pump air locking - 05/24/21 02:20 AM

Bizzare. Same brand/gph pump?
Posted By: Droyhef

Re: Livewell pump air locking - 05/24/21 03:51 AM

No its a different brand. Its what the had on the shelf at walmart. Im leaning towards trying a rule pump. This thing has an optional port in it with a plug where you can mount it at an angle if you want and im wondering if that isnt holding an air pocket. It put out plenty of pressure once and a while.
Posted By: forkduc

Re: Livewell pump air locking - 05/24/21 02:50 PM

Same with my Skeeter
Posted By: Stump jumper

Re: Livewell pump air locking - 05/25/21 12:25 PM

Buy a pump that has a replaceable cartridge. It is much easier then replacing the whole unit. Put some quick connects on the wires. I have Attwood Tsunamis in my Champ and they work great. I can change a cartridge in minutes on the water.
Posted By: Micheal

Re: Livewell pump air locking - 05/29/21 02:10 PM

One thing to consider is, is the impeller tight on the shaft. I have seen them be loose out of the box. They are press fitted. They may work sometimes and not other. Livewell pumps work when there is water present. My question is where is the air coming from. Sitting at rest or even at idle there should be water in the pump. Even after coming off plane water floods the pump. If there is air present the air is forced up and into the hose. Walmart is not known for selling quality.
Posted By: Droyhef

Re: Livewell pump air locking - 05/30/21 12:19 AM

Impeller isnt loose, it will pump hard with good pressure sometimes. I pulled the old one apart and sawed the housing open to see how it was setup. The shaft is flat on one side mated to the impeller. You are right about walmart. I see your sigy, what brand do you replace with?
Posted By: Micheal

Re: Livewell pump air locking - 05/30/21 02:13 PM

I use Marpac or Johnson pumps (spxflow.com). They are both cartridge pumps. They also come in either straight or 90 degree configurations. They come in various GPH ratings. I normally use the 750 GPH version. Easy to install and easy to maintain.
PM me if you have any questions.
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