Gone through 5 water pumps in 2015 cedar creek

I would need a picture of the installation and the crack to give an opinion.

Can't really provide a picture now since I now have the pump in a small tub to catch the drip. Sorry, gotta keep the basement dry.
And after looking closer it's more of a pinhole than a crack, but it's dripping enough to fill a small tupperware container overnight.

Sounds like a warranty defect with a pin hole. If you have a receipt I would contact the seller or the manufacturer.
Otherwise move on (again :( ) with a new one.

I have found that just blowing out the lines usually leaves enough in the bottom area of the pump to cause freeze damage. The design of the pump just retains water in low points. I blow out my line but finish off with about 10 seconds of pumping antifreeze into the pump.

Freeze damage is about the only reasonable thing I can think of, too.
9 years on first pump an Aqua flow, replaced with same. Switch went bad on it and they won't sell parts.
Either it was freezing, or anything else, I cannot come up with it.

5 pumps in 5 years and you don't use the pump. Over tight or freezing, head south sooner.

My pump is 27 years old. Does it always crack in the same place? At the same time of year ?

Do like Old Biscuit says and just cap it off if you don't use it.

Have installed a shutoff, and shurflo is replacing the housing portion of this pump. No one can explain why. Basically all the pumps have leaked generally in the same place. To those that insist the pump is freezing, this trailer has not seen temps below low 40 upper 30, if that is freezing, I guess we better start wintering in Hawaii.

I haven't used a Sureflow but in the years here, I think this is the first report of this problem. I thought freezing, but you ruled it out. Then the installation is wrong,in some way, or something is hitting it hard. I don't see a photo and installed which might tell a lot. On the Aqua flow four screws through four rubber vibration isolators, two hose quick connects and on quick connect 12v electrical plug is all there is. Only possible problem would be using a power driver to tighten the screws/bolts down but I think they are stepped on ours. The Sureflow is almost exactly or exactly the same as the Aqua Flow best I remember.
Ours is 55psi at 5.5 gallons a minute I think and it would break of its on accord quicker than the Sureflow you have of its own accord.
Have a Good Mobile Tech install the next one and look at the whole installation.
Water pumps are probably number two in the number of jobs they get called for right behind water heaters, and maybe number one.

Our pump is the original unit on our FW, purchased new in 2010. We winterize every year with antifreeze and boondock more than we ever use hookups. Our water pump is in the front basement behind a removable wall.