New MMI Flexible Impeller Pump

[macgyro]

Which direction to bend the blades of the impeller?

I'm replacing my water pump impeller after an unknown number of hours on the new (to this boat) used engine. I'm curious if the blades in the attached photo are bent in the correct direction? This is my old impeller that I haven't removed yet.

Thanks!
Dean

[JOHN COOKSON]

I'm replacing my water pump impeller after an unknown number of hours on the new (to this boat) used engine. I'm curious if the blades in the attached photo are bent in the correct direction? This is my old impeller that I haven't removed yet.
Thanks!
Dean

Did the pump pump water before you took the face plate off? If so the blades are oriented correctly.
The easy way is to install the new impeller and bump the starter then the blades will orient correctly because the direction that the blades orient is fixed by the direction of engine rotation. (assuming the input and output hoses are not switched!)
If you want to delve into it a little deeper there should be a larger space between the blades when the impeller passes the input opening and a smaller space between the blades pass the output opening thus forcing the water or coolant out of the pump.
You can take it from here. In your next post tell us if the blades are oriented correctly or not in the picture.

TRUE GRIT

Edit: To start a new thread scroll down the on forum home page to "discussion topics". Click on the topic you want. The new thread button will be in the upper left. You'll get more responses if you start a new thread.

Edit #2: If the pump doesn't pump try priming it by pouring down the input hose while holding it vertically into the pump.

[ndutton]

Yes, impeller vane direction is correct.

[JackConnick]

Dripping MMI Pedestal Pump

I have a newish (maybe 2-3 year old) MMI Pedestal water pump on my late model A4.

No matter what I do I am getting a steady water drip from the lower thumbscrew area. I've felt around the pump and hoses and it's definitely coming from the lower place on the pump.

I've cleaned it up thoroughly and replaced the oring. Still dripped. Gave up on the oring, and tried copper RTV which usually seals about anything, but it's still leaking.

The oring is stupidly tiny. Is there a paper seal available as well? Better backplate? I'm sort of at a loss to get this fixed right now.

Thanks,
Jack

[Don Moyer]

Leaky MMI pedistal pump

Jack,

It sounds like you may have a small defect in your housing. If you give me a call at (717) 766-8777 I'll see if we can work something out to correct the problem. In the meantime, you may be able to correct the leak by installing a standard back plate gasket, or by cutting a temporary one out of a brown paper bag. Don

[roadnsky]

No matter what I do I am getting a steady water drip from the lower thumbscrew area.

Could it actually be leaking from the WEEP HOLE and running to the back of the pump?
Did it just start leaking OR was it after a maintenance on the pump and you opened up the back?

[blackdove1256]

Pedestal Pump

Need some help. Looking at the pulley side (front of the pump) which port is the inlet and which is the outlet. Also, when I ordered the pump I didn't order the belt. What size drive belt do I need. Many thanks.

Gregg
Cal 29

[sastanley]

blackdove...we need more details.
On my MMI502 pump, looking at the pump from aft the port side of the pump is the inlet, and stbd side is the outlet. My pump is mounted on the aft stbd side of the motor and is gear driven by the same as the distributor.
If your pump is driven by a pulley (alternator pulley or PTO on the flywheel??) you may have something different.

[Greg Kingman]

Water Temp Gauge Sending Unit Placement

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.)

I am looking at this picture with gate valve, and wondering if mounting the water temp sending unit where he has a plug, might give one the most accurate measurement of the temperature of the coolant circulating through the engine?