Using a Mag7 as an external pump

[TMIB]

I have 2 Mag7 pumps, and they both leak around the seal when used externally. I opened them both up, and thoroughly cleaned the "seat" area and the impeller housing. The o-ring is in good shape, and the screws holding the housing are solid. Still they both leak, though now the leak seems to be coming from the end opposite the impeller.

I'm about ready to break out the aquarium sealant (100% silicone) and goop the hell out of this pump in an effort to seal it. Am I missing something obvious? I'd heard that this pump should be able to be used externally (so long as it is primed, of course) but to have both of them leaking in exactly the same manner makes me skeptical. Apart from difficulties in taking the pump apart later, do you forsee any problems with sealing it with silicone?

Thanks,

--TMIB

 

[bowfront]

I've run a Mag 9.5 externally in the past without any leaks or problems but never tried a Mag 7, which is a different shape housing. Are you sure that the leak is not coming from the treaded in/out connections, which are usually very loose and need plenty of teflon tape wraps when plumbed?

 

[TMIB]

The threaded connections have been wrapped with teflon tape, and are tight. It did not appear that they are leaking, but I will re-inspect them closer tonight and see if perhaps I misled myself into believing that the leak was coming from elsewhere.

--TMIB

 

[rotorh60]

I am running two MAG 12's externaly, and after doing routine cleaning, one of them started leaking. After I changed the gasket on impeller cover, leak went away. HTH

 

[Iron]

try plumbers silicone grease from Gunk. use it on the o ring it will help

 

[sese]

My mag 5 leaked when I tried to use it externally. It works fine submersed, however. I would like to see how you solve your (our?) problem and still keep the pump serviceable.

Eric

 

[TMIB]

I can open it up to clean it, but then I'd have to reapply the silicone seal.

To open it, I'd have to rip open the sealant I put on.

It basically means that anytime I clean it, it will be offline for 24 hours while the new silicone cures.

I see this as a temporary pump anyway. For the application I'm using it for (a recirculation system) I need a lot higher flowrate than the mag7 will provide.

--TMIB

 

[TMIB]

Well, I ended up putting aquarium sealant all around the impeller housing, and around the seams at the top end. It looks a little funny, but it works fine now.

--TMIB

 

[Ben1]

I had the same problem with my Mag 7 and used silicone also. Maybe its just this model?

 

[sese]

Can you still open it up to clean it?