Black water tank overboard pump

[cosmo]

Currently have a Jabsco 59090 diaphragm ‘self priming ‘ pump. I have never been real impressed with this pump in the rare times it has been used. It never seemed to prime itself without a lot of run time. Last week I replaced the diaphragm and now it won’t prime at all. I should add, my tank is clean with fresh water in it and just doing pump maintenance.

Is there a way to keep it primed/get it primed or perhaps a stronger-self priming diaphragm pump?

Thanks

 

[Alaskaflyer]

How tall is the "lift" from the bottom of the tank to the pump location?

 

[cosmo]

Maybe...2”?

 

[Comodave]

Currently have a Jabsco 59090 diaphragm ‘self priming ‘ pump. I have never been real impressed with this pump in the rare times it has been used. It never seemed to prime itself without a lot of run time. Last week I replaced the diaphragm and now it won’t prime at all. I should add, my tank is clean with fresh water in it and just doing pump maintenance.

Is there a way to keep it primed/get it primed or perhaps a stronger-self priming diaphragm pump?

Thanks

It used to prime, you changed the diaphragm and now it won’t prime. I would go back and make sure the diaphragm is installed correctly or isn’t damaged. When you change a part and the problem goes off in a new direction I always go back and make sure I didn’t inject a new problem. Good luck.

 

[skyhawk]

I used to work with industrial pumps of all sorts....
I don't know that pump...but for a diaphragm pump, seems like a check valve issue to me.