Kohler 5E impeller rotation

D

DaleM

Member
Aug 5, 2009
690
Mt Airy, MD
Boat Info
340 Sundancer
Engines
Twin 8.1 Horizons
I've looked around and can't find which direction the water pump rotates if looking at the end of the water pump. I'm replacing the impeller and couldn't find references posted here either. Only "note direction when removing"

My problem in "noting direction" had to do with the fact that I had to replace the impeller without actually being able to see it because my holding tank is in the way and prevents me from actually looking at it. As I pulled the old one out, it let go quick and flung out of my needle nose pliers. That's why I'm here - I couldn't tell which way it was in there.

A local dealer swore it wasn't an offset impeller/pump but based on the shape I can tell otherwise.

Does anyone know which way the pump rotates if looking at it head on? I don't want to burn up this new one right out of the gate and I don't think based on how tight it was to get in that the vanes will orient themselves.

Thanks!
 
Hi southpaw II, I saw that earlier too and that article too only references proper direction: "place the impeller on top of the pump and twist it in the proper direction to get it started (vane tips are trailing rotation)".

I am trying to figure out that "proper" IE, CW, CCW from the standpoint of looking at the pump impeller rotation. Worst case I will go up and pull off the cover and cycle the start switch to see what direction it turns.
 
I believe it is clockwise. But it is offset so it will correct very quickly especially if you put some soap on it. Do you have the old impeller? Put it back in and start the generator - then note the rotation.
 
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It's pretty easy to see which way the blades go. If you know which side is the water intake, the impeller rotates such that the water will travel the longest distance around the inside of the housing:

DSC_0295.jpg


You'll note that the intake and output are on one side. The impeller is offset so the chambers are expanding and sucking water in and then the chambers are squeezed as they approach the output... Just remember that the water has to travel the longest distance inside and position the blades with that in mind. On the pump shown here, the intake is on the left and the output is on the right. Longest travel distance for the fluid sucked in would be clockwise in the pump.
 
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The old impeller was.... misleading. As screwed up as this is going to sound there were vanes going in BOTH directions. The only thing I can think is that it was put in originally "cattiwhumpus" and it stayed that way.

Unfortunately I couldn't even see where the bite marks of the pliers were to get a reference point. My concern is that because it's such a B to get in there initially that the vanes won't correct. It is the right impeller because when the old one is forced to straghten out it's the right diameter. I did lube it up though and any kind guy would before putting it in. :)
 
The impeller blades can/will flip if there is a blockage in the circuit as well... And they may not go back correctly. That's why if you get a blockage (like sucking something up), you may have damaged the impeller and not really know it until it blows up.
 
Four Suns, the logic makes sense. I may have to find a mirror small enough to see the offset. I'm not kidding when I say the distance I'm working within is less than a 1/2" between the pump and the holding tank. I don't remember which hose is which so another trip up to it armed with this information may be what it takes.
 
You should be able to look at your manual and find which ones are input or output... mine has the input on the bottom and output on the top...
 
DaleM said:
I don't remember which hose is which so another trip up to it armed with this information may be what it takes.
Click to expand...

With the impeller shaft pointing at you, the hose barb for 3/4 id hose on the right side of the pump housing is the inlet, the impeller sweeps CW to the discharge on the left side of the housing that leads to the heat exchanger.

A new 5E impeller is capable of rolling the vanes over if the pump rotates CCW when the engine is shut down. I jogged the engine once (plug wires were pulled off) with the impeller cover removed to see how the vanes reacted if the engine were to rotate CCW briefly when the engine shut down. The vanes on a new pump are flexible enough to correct themselves when the engine cranks over again. Once the rubber vanes age and get brittle, the vanes crack or break.
 
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Stray Cat,
Thanks for the information. I do have a new impeller. Based on your description I have installed the impeller opposite of what is described (vanes sweeping ccw)

I really appreciate all the effort by those responding. I'll pull the plugs and jog the started to see which direction the shaft is going and post back here. I want to avoid what I think I saw which was a portion of the vanes going one direction opposed to the rest. That seems to reduce the overall waterflow.
 
Same generator. I can confirm the vanes will set-up properly on a newly installed impeller regardless of how you put them in but it will cause some minor stress on the vanes as they snap around. Best to put them in correctly.
 
The vanes being all catty wumpus won't effect the flow rate...they can be pointed/stuck in any position and as long as the blades are there, the flow will be the same... but it will strain the blades if they don't go back to the way they should be and get stuck going around...

Here's one fin that did not flip over:

DSC_0296.jpg
 
DaleM said:
Stray Cat,
Thanks for the information. I do have a new impeller. Based on your description I have installed the impeller opposite of what is described (vanes sweeping ccw)
Click to expand...

Just to clarify, the shaft rotates CW, which means the vane will be folding like the impeller in Gary's picture above (except for the one vane)
 
Just as a side note... You'll notice that the impeller picture with the bent fin also shows a permanent set in it all the way around. That impeller was out of a brand new sherwood water pump that had never been used. Obviously, it needed a new impeller anyway because of lack of use. An impeller that has not been used for awhile will set in a deformed position and that WILL affect the water flow. The blades on the highly compressed side of the pump may not expand to touch the pump walls all the way around the circuit...
 
DaleM said:
Hi southpaw II, I saw that earlier too and that article too only references proper direction: "place the impeller on top of the pump and twist it in the proper direction to get it started (vane tips are trailing rotation)".

I am trying to figure out that "proper" IE, CW, CCW from the standpoint of looking at the pump impeller rotation. Worst case I will go up and pull off the cover and cycle the start switch to see what direction it turns.
Click to expand...

Touch the shaft with your finger and bump the start button....you will feel which way the shaft rotates.
 
:thumbsup:I just replaced my impeller and saw what goes on in there as i can see it clearly with open space. the impeller only touches one side of the housing at a time. The vains are fully outwards when on the other side of the circle. You can install the impeller with dish soap and it only turns 1/2 rotation before it corrects itself, if you guessed wrong. Also one note.... be sure to count the old impeller parts to stop any chance of heat exchanger blockage
 
Tumbleweed, good information. I should be good then. I lubed the impeller so I'll just pull the cover and pulse the start to make sure things flip around good by feeling things with the palm of my hand (I'd like to keep my fingers). Luckily my impeller was fully intact when I pulled it so parts shouldn't be lingering. The only problem is like the picture posted the fins were stuck in the bent position with the old one. My waterflow was probably affected.
 
FYI - CCW rotation for mine

I toggled the starter with the cover off and could feel that the impeller rotates counter clockwise when looking in from the pump end. One of my vanes was going the wrong way and after numerous toggles on the starter it did not right itself. I pulled it out and forced all the vanes in the right direction.

Just thought I'd follow up and close this one out. Who knows, maybe they rotated different directions with different years, models, etc....
 
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