yesterday had to pull over with my HF because I saw the watertemp rising to almost 100deg and the heater gave only cold air. It had ran perfect for about 200miles and just 10 minuter after diner on the way home it happend. The lower waterhose connecting to the waterpump was cold and the water in the radiator just warm, not hot. There was no flow to be seen in the radiator with the engine idling with the tap off. I suspected the waterpump was not functioning and guessed the impeller was loose on its shaft. The reason I thought about this was the fact that I had overhauled the pump 5000km's before and wondered if the construction without a keyway for the impeller but just a 8mm nut to clamp it would work. It didn't. I removed the waterpump lid and could turn the impeller by hand. Tightening the nut again brought me home but I find it flimsy to say the least.
I do not know if all waterpumps have this arrangement as this pump is an original S1 pump.
waterpump coming loose
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Justin
Re: waterpump coming loose
I believe there was a tab washer under the brass nut, originally.
Anyone confirm this?
Anyone confirm this?
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William
Re: waterpump coming loose
Yes, the tabwasher should be there but that just prevents the nut from coming loose. If for some reason the impeller gets some play it can rotate regardless of the nut. In my case when installing the (NOS) impeller on the (NOS) shaft the nut was torqued to 2kgm. As is ok for an M8size nut fitted to a shaft which is cut for the tabwasher. Yesterday after undoing the tabwasher the nut could be tightened further. The impeller bottoms against a boss on the shaft. I think a keyway is the safest thing but maybe lancia thought about an obstruction in the pump which should stop the impeller but leave the shaft rotating as this could jam the chain if it stopped too.
Would locktite or another threadlock do the trick?
Would locktite or another threadlock do the trick?
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Huib
Re: waterpump coming loose
It is a problem. It is twofold. The impeller may stop turning and water may leak between impeller and shaft and thus get past the mechanical seal.
A keyway sounds like a very good solution but how are you going to prevent water leakage?
Locktite sounds like the best solution.
A small weld or a hit with a center point would also prevent the thing from coming loose but would not prevent leakage.
Turning a new shaft with left hand thread and cutting thread in the impeller might do the job. Sorry, the standard right hand thread as the impeller turns counter clockwise.
A keyway sounds like a very good solution but how are you going to prevent water leakage?
Locktite sounds like the best solution.
A small weld or a hit with a center point would also prevent the thing from coming loose but would not prevent leakage.
Turning a new shaft with left hand thread and cutting thread in the impeller might do the job. Sorry, the standard right hand thread as the impeller turns counter clockwise.
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William
Re: waterpump coming loose
Am I right in thinking that I'm not the first to discover this problem? If it is a known problem more Fulvia's should have had this fixable breakdown or worse, a blown headgasket...
If not, the design is satisfactory. I can't find any assembly instructions regarding threadlock in the maintenance manuals.
If not, the design is satisfactory. I can't find any assembly instructions regarding threadlock in the maintenance manuals.
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Huib
Re: waterpump coming loose
It happens occasionally, now as well as in period It is a weak point in the construction. Less on new pumps. More frequently after overhaul.
I have been thinking about it in the meantime. A better idea is perhaps to turn a groove for an O ring in the lower part of the spindle where the impeller sits to stop water leakage along the spindle. And a key in the upper part.
I have been thinking about it in the meantime. A better idea is perhaps to turn a groove for an O ring in the lower part of the spindle where the impeller sits to stop water leakage along the spindle. And a key in the upper part.
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Huib
Re: waterpump coming loose
If one uses a key like on the front of the crankshaft it would not work as the groove in the impeller has to be from top to bottom. The O ring would have to be at the top and the key at the bottom.
Or use a key like on the main shaft of the gearbox and hold it in place with the nut.
Or use a key like on the main shaft of the gearbox and hold it in place with the nut.
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P. de R. Leclercq
Re: waterpump coming loose
I would use Loctite 271 (Red) for this.
However, there is another, but perhaps difficult alternative: a sintered washer.
Difficult, because you would have to source one.
The idea came to me from my experience rebuilding Volumex blowers. The rotors have to be mounted with just 0.004" clearance. They are not keyed or splined but clamped with these special washers.
I suppose that in the end a new pump is the answer!
Paul
However, there is another, but perhaps difficult alternative: a sintered washer.
Difficult, because you would have to source one.
The idea came to me from my experience rebuilding Volumex blowers. The rotors have to be mounted with just 0.004" clearance. They are not keyed or splined but clamped with these special washers.
I suppose that in the end a new pump is the answer!
Paul
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william
Re: waterpump coming loose
The pump is new. Housing is original magnesium S1 (without tempsensor provisions) shaft and impeller are original Lancia parts and never used.
I'm thinkin g in the line of a selfmade tabwasher with an extra tab to be used as a key. I only have to grind a very small keyway into the impeller. (6mm is enough) I can use a 'dremel' for that.
I'm thinkin g in the line of a selfmade tabwasher with an extra tab to be used as a key. I only have to grind a very small keyway into the impeller. (6mm is enough) I can use a 'dremel' for that.
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P. de R. Leclercq
Re: waterpump coming loose
Yes, that's one solution, and should prevent movement between impeller and shaft.
Given the parts are new, there really should be no problem. I would think a drop or two of Loctite 271 on the shaft and thread would be more than adequate.
Paul
Given the parts are new, there really should be no problem. I would think a drop or two of Loctite 271 on the shaft and thread would be more than adequate.
Paul