New MMI Flexible Impeller Pump

[Jack Cornish]

impeller pump repair kit

I'm rebuilding the impeller pump and am having difficulty in driving the shaft deep enough so that I can install the seal and snap ring. (instructions fig. 14-15) The shaft/bearing is slightly below the snap ring groove but isn't in deep enough for the seal and ring to fit. Any suggestions?

[Jack Cornish]

pump rebuild

Still trying to sort out pump rebuild. Took out a seal (oberdofer A54630) which is metal. The repair kit supplied a plastic seal. Bearing fits snug in the casting but, there is no room for the larger seal that goes under the snap ring.

Is this the right rebuild kit? The unit doesn't have a grease fitting and I don't remember a seal under the snap ring. Do I just have the wrong parts?

[Kurt]

I'm curious too as I will be using the kit to rebuild my MMI pump soon. Anyone done this before or have some insight into this issue?

[Bryanbt]

Removing lower blt on old water pump

Am about to install my new MMI water pump. The extender bolt should help install the new one. But first I have to get the old one out. The space is so tight in my C&C 30 that I can not even get to where I can see (let alone reach) the lower bolt. At the moment it looks like I'll have to disconnect the fill hose to my gas tank and the tank's copper vent line. Even then, I am not sure I'll be able to get to it.

Is there such a thing as a long socket (at least as long as your extender bolt) that would make getting out the old one any easier? What size socket would it be?

(any other suggestions...or contortionists for hire???)

thx

[67c&ccorv]

Hi Don,

Here is a shot of your MMI Flexible Impeller Pump and Extender bolt as just installed on "Dulcinea", my 1967 C&C "Corvette". It is a beautiful piece of kit! (The plugged take-off with the gate valve is for flushing and running the engine on the dry.)

[Don Moyer]

Great job! Thanks for the nice shot of your installation.

Don

[luvmyi36]

God bless the extension bolt!

[sailalibi]

new flexible impeller flange pump configuration

I just received a new flange pump to keep as a spare and noticed that the oil seal seems to be internal to the pump body instead of just under the snap ring on the flange side of the pump (as in the old pumps and repair procedures) . The old rebuild procedure (figure 3) matches the new procedure (figure 3) but the new procedure has figures 12-14 showing the oil seal moving into the pump thus exposing the bearings to an oil bath I guess. Is this correct?

[Don Moyer]

MMI water pumps

We did make this small change in the location of the oil seal in our latest pumps. The oil seal is now on the impeller chamber side of the bearings so that if a lip seal should leak, the raw water will not have direct access to the bearings. Any repair kit bought since this change was made will contain the correct parts and instructions to assemble the pump with the oil seal in the new location. Any questions can be directed to: info@moyermarine.com Don

[sailalibi]

Thanks for the update. Can the older pumps be rebuilt the new way?

[JonWannabe]

New Impeller not pumping as much as the old one

I replaced the impeller as a 'just in case'. No issues once I was able to get the old one out. Sadly it seems to be spitting less water than the old one did. I thought I was doing a good deed by putting a bit of lithium grease on the inside of the area thinking it would create less friction on the spinning rubber. Did that mess things up? (good thing I got a spare gasket). Thanks

[Don Moyer]

For Sailalibi post #25: Yes, thanks for asking. All of the current kits will have the new configuration and appropriate instructions. There has been no change to the basic housing. The only change has been to the bearing stop ring on the shaft so as to move the bearings approximately 1/4" to make room for the oil seal on the impeller chamber side of the bearings. Don

[lhbradley]

New MMI pump - impeller replaced - end plate leaks now.

Replaced the impeller on my MMI water pump while it was on the engine. Used some string to bend the blades so it would go in easily, then pulled string out. Guess I didn't get the thing all the way in, since when I install the end plate, I get some leaking. Access is difficult. I tried using a socket against the impeller center part and some light hammer taps - it looks like it is in OK, but still get some leaking around the bottom of the plate. It is safe to hammer the impeller in more (using a piece of wood to protect it? Can I use some liquid gasket gunk on the end plate (outside of the sealing ring? Or should I bite the bullet and pull the pump off to do it?

Thanks

[BunnyPlanet169]

The impeller on the MMI pump usually goes in pretty easily. It's a slip fit on mine. Don't bang on it....

A leak is more likely the result of a missing, or damaged, or pinched o-ring. It's tiny, as in ridiculously teeny tiny. Are you sure it's there? Confirm presence and installation of o-ring. Make sure the mating pump flange is clean.

[Administrator]

We did make this small change in the location of the oil seal in our latest pumps. The oil seal is now on the impeller chamber side of the bearings so that if a lip seal should leak, the raw water will not have direct access to the bearings. Any repair kit bought since this change was made will contain the correct parts and instructions to assemble the pump with the oil seal in the new location. Any questions can be directed to: info@moyermarine.com Don

Bumped.

Bill