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Discussion Starter · #1 ·
I am in the process of putting my engine back together and my new water pump seems very unbalanced and turns uneven. Has anyone experienced the same and driven with it? I am reluctant to wait for a replacement as the driving season is over soon in Denmark.

Video of water pump spinning:

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Looking at your video, in the first few seconds, it seems like the outer rim is straight and not wobbly so maybe the goofiness in the centre is just an optical illusion. I would focus more on the outer edge, can you put a rubber hose on the front of the pump to a drill and spin it that way?
 

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Discussion Starter · #4 ·
Looking at your video, in the first few seconds, it seems like the outer rim is straight and not wobbly so maybe the goofiness in the centre is just an optical illusion. I would focus more on the outer edge, can you put a rubber hose on the front of the pump to a drill and spin it that way?
Good idea, I will try that tommorow.
 

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Looking at your video, in the first few seconds, it seems like the outer rim is straight and not wobbly so maybe the goofiness in the centre is just an optical illusion. I would focus more on the outer edge, can you put a rubber hose on the front of the pump to a drill and spin it that way?

It does look like the outer edge of the pulley tracks straight...also looks like the center is offset. Don't understand how both could be. You could have a machine shop touch the center to get it concentric perhaps.
 

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The pully is rotating in an elispe and is defineitly not centered on the impeller shaft. You should ask your supplier for a replacement. If you intend to use this pump I suggest a looser than normal V belt tension to allow for the tension and release with every rotation a tight belt will destroy this pump very quickly. And is the pump a brand name pump or a no named generic ?.
 

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In my opinion the video does not obviously show as large of a wobble as one would expect from the shared photos. A handheld camera makes it difficult to tell. It is still possible to have the appearance of the hub of the pulley seem off, and the actual V groove spin true - depending on the jig. Fran - you are definitely correct that the "tower" of the pulley is not centered but it doesn't need to be for the outer portion to run true.

The only real way to tell is to mount a dial indicator or similar and check the runout at the outer part of the pulley. You could also make a small pointer and bolt it through one of the water pump bolts, and measure the delta between pointer and outer pulley carefully at many points. It is possible the center "post" of the tower is not actually centered vs the V groove in the pulley. The way these are usually manufactured, the jig holds the outer pulley and spins for the weld so it will run true on the belt. Does it look suspect? Yes, but it may actually be OK.
 

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Do you mind sharing: where did you get this pump? It does not look like the Italian-made ones I'm used to from Centerline. The casting and pulley, in particular, look quite different. And, I've not encountered those "tested" stickers before.
 

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BB members need to know about sources for poor aftermarket components. It is not uncommon for our good suppliers to end up with poor, made who-knows-where-components.
This has also happened with oil pumps.
 

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"The only real way to tell is to mount a dial indicator or similar and check the runout at the outer part of the pulley. "

Agree with this, shoddy as the machining job is on the hub, it may run true. Which makes me wonder if the flat spot was placed there for balancing???
 
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Discussion Starter · #16 · (Edited)
Do you mind sharing: where did you get this pump? It does not look like the Italian-made ones I'm used to from Centerline. The casting and pulley, in particular, look quite different. And, I've not encountered those "tested" stickers before.
I bought it from a danish importer, MyAlfa.dk. I just bought a new one from OKP, and its also a tad unbalanced :( It looks like the exact same make, but without the"tested"" sticker.
 

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I don't think the hole is mis-centered, it looks like the pulley is just cast a bit weird. I would check it with a dial indicator as noted above: if the surface where the belt rides is true relative to the axle then you're probably okay.
 

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Discussion Starter · #18 ·
I don't think the hole is mis-centered, it looks like the pulley is just cast a bit weird. I would check it with a dial indicator as noted above: if the surface where the belt rides is true relative to the axle then you're probably okay.
Just made my own little dial indicator.

 
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