Posted by Doug Linden on June 25, 1997 at 16:01:05
In Reply to: Water pump impeller clearance
posted by DJ.Voyce on June 25, 1997 at 10:28:56
: Help again please. I have just stripped my water pump & found all sorts of ingenious ways of stopping the shaft floating back & forth in its bearings, however these strange modifications were all holding the impeller in the fully forward position. My question is should there be a specific clearance between the impellor & head face,(I figure 0.020" to 0.040" should do) or would this increase the flow rate too much as I see that this is frequently mentioned as a cause of overheating. To achieve this clearance I would need to fit a spacer of approximately 7/16" betweet the impellor & housing.I would appreciate any input available. D.J. There are a number of ways to take up the end play on the shaft, which is essential to keep the pump from leaking and reduce wear.Excessive end-play allows the shaft to move in and out which lets it function like a pump allowing water to escape. The two methods I've used are to tap the end of the shaft to accept a round head brass screw which is then ground down to give the proper clearence.The other method is to use a shaft collar under the fan assembly.Both methods work fine. Doug |