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rederic48
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Hello
I needed to change my water pump on an early engine and found an acceptable one amongst my spares. However, the v belt pully is nearly off the shaft. I have read conflicting discussions regarding the method of adjusting its position I.e using a hydraulic press and/or using lock thread compound. Can anybody please advise?
Thanks

redracer
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The belt pulley is not adjustable(I have never heard anyone try to shim it); the center portion fits around the protruding nose of the hub(where the 4 bolts go).
As for your "find" of another one, unless it has been rebuilt(preferably using the 3G seal), you're asking for trouble.
The original ones had the carbon disc(embedded in the seal) rub against the steel nose of the impeller, and under "ideal" circumstances, the carbon would wear the steel nose so eventually you had a small leak in the lower weep hole of the housing. However, what usually happened was the impeller would grab the carbon disc and rupture the seal, causing a small "flood" and possible engine damage from lack of coolant.
Having rebuilt well over 300+(stopped counting in the late '90s), I would again advise NOT using your "spare".
keep us posted, brue

Esprit2
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The pump pulley's V-belt groove must be in the plane of the crankshaft pulley's V-belt groove. There's no built-in step that correctly positions the hub on the shaft... and it's the hub that locates the V-belt pulley.


Is the pump you found in your stash "original" J-H? As in, the way it came from the factory? "IF" it is, then remove the pulley, and measure the distance from the front face of the hub to the rear face of the pump housing. When you press the hub back on during the rebuild, push it on to the same dimension... put it back where you found it.

If you have zero confidence that the pump and hub location are original/ correct, then use 3.875" (98.4mm).

While pressing the hub on in a hydraulic press, it's difficult to get in there and measure the distance from the hub's front face to the housing's rear face. Instead, I prefer to select a stack of feeler gauge leaves that are a snug slip fit between the nose of the pump housing, and the hub. Then when pressing the hub on, lay the stack of leaves on the housing's nose, and press the hub on until it makes concact with a snug slip ift.

If you don't know the history of the pump, or if it's hub is in the correct position, then I don't recommend the feeler gauge method. All you would be doing is duplicating what 'is', even if it's wrong.

See the attached cross-sectional drawing.

I agree with Bruce. If your spare is old and used, then it's at death's door as is. It might be a good core for a rebuilld, but don't trust it as-found in the bottom of some box.

Regards,
Tim Engel

Attachment: Water Pump - 9XX Rebuild - Cross-Section, Dimensioned, JH 907.jpg (Downloaded 53 times)

DonBurns
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Has anybody used the new manufacture water pump from Martin Robey with replaceable pump / separate housing? Their Part # 94356C. Pretty pricy (especially with shipping), but possibly an option for someone with no rebuildable core.

discogodfather
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DonBurns wrote:
Has anybody used the new manufacture water pump from Martin Robey with replaceable pump / separate housing? Their Part # 94356C. Pretty pricy (especially with shipping), but possibly an option for someone with no rebuildable core.

Try Gary Kemp he had aluminum versions (machined) that weren't too bad in price. Unfortunately his ebay store is not active at the moment (maybe holidays?) but there might be other ways to contact him.

If I ever had to replace the stock unit I would get that aluminum version.



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