View Full Version : water pump part 3, assembly

06-27-2007, 02:47 PM
Before assembly I cleaned my housing and painted the pulley. I painted the housing after the bearing /shaft was installed. I was careful to not get any paint in the bores or on the shaft and applied only a thin coat to the pulley belt area so the belt can easily wear away the paint where it makes contact.

One more thing before starting. I contacted John Crane, Inc, which is a company that produces seals and talked at length to one of their technical reps, who recommend one of their seals, S106MAST, which is a ceramic seal with stainless components. He also recommended Harold Bishop’s HdrK CO, Inc. in Albany, Indiana. (765) 789-4406. I called Harold and gave him the measurements I took (see part 2) and he recommended the following shaft.
W2446; shaft length 4.469; pulley end length 1.081; vane end length 1.859; shaft diameter 0.6267.

Harold had both the seal and bearing/shaft in stock and I had them in a couple days. I add that Harold knows his stuff and was eager to share his knowledge. He was the source for the dimensions of the push tool for the seal shown later in this article.

The reason I did not include those dimensions is that if you do not order the same seal the dimensions may be different.

Then it was time to reassemble the water pump. This is really pretty easy but care must be given to get the spacing correct. A press, set of feeler gages, caliper, and a tool to get the correct tension on the seal spring will be needed.

I will cover the process in order of the procedure. The first step being the installation of the bearing/shaft in the pump housing.

There are two things to be careful to do here. The first being to make sure to have the shaft orientated properly so the correct end lengths are in the correct position. The second is to have something to push the bearing in by only making contact on the outer bearing race. Here I used a deep socket that is large enough to sit on the outer race and small enough to fit in the housing bore with out getting stuck. It also must be long enough inside to not interfere with the end of the shaft.

I then placed the housing, bearing/shaft, and socket in the press. Care must be taken to have these parts in alignment and square to the press. It is also important to have clearance below the housing for the shaft to clear.


These photos show the location of the bearing in my housing. This does not have to be within any particular dimension but you should center the bearing to the bore surface that supports it.

These photos show how the seal fits in the housing. I used some locktite on the flange when assembling to help the flange press in and to help it seal in the housing. I did not use any sealer on the shaft but the same could be done there. Do not get any on the seals themselves.

This is the seal driver my brother made for me. It is brass only because it happened to be what was handy, it could have just as well been made of nylon or UHMW or steel. The second photo shows how the seal fits in the driver. It is important to use a press to install the seal. Using a hammer would likely cause damage to the ceramic seals.

The following sequence of photos show the actual installation of the seal. Again, make sure all parts are aligned and vertical in the press. For this process the shaft should be on the press platen. Notice that as the seal gets very near to being seated that the tool makes contact with the flange and from that point installs both the shaft and bore portions of the seal as a unit in a compressed state. This is the reason for the tool. To place the proper tension on the spring so the seals do not leak and so they are not so tight that they wear quickly.






This step is very important to the function of your pump. The spacing between the vanes of the pump and surface in the mating housing needs to be about .030”. If much more the pump can have a tendency to cavitate. If it is too close the pump may rub or just work harder. I measured the vane hight on the impellers of both my old pump and the Asian replacement I purchased. With both the vane height was not consistent between the four vanes on each impeller. They varied by as much as .007”.

The next part of this step is to measure the thickness of your pump gasket. Mine is .032” using my caliper. Remember that the caliper accuracy range would indicate that that may be from .030” to .034”. A side note here, if for any reason you remove your water pump it is important to replace the gasket with a proper gasket to maintain the pump spacing.

With that in mind I pressed the impeller on the shaft. I did not press mine fully to the shaft end, but left a small amount of space.

I then placed the pump in the mating housing and using a feeler gage went around and checked the amount of space between the castings. Because of the variance of the vane heights there was a small difference in readings. Because I did not want the impeller to rub I used the largest readings. By using this method and some simple math I determined the remaining distance to push the impeller. I made a spacer of the required thickness and placed it under the impeller in the press and pushed it to its final position. I then rechecked and was satisfied when the impeller just cleared the inside of the mating housing. The gasket thickness then giving me the proper spacing.

This photo shows the final position of my impeller.

It is fairly straight forward to install the pulley. But remember to push on the opposite shaft end. If the other end is inside the impeller use a small socket or other piece on the shaft inside the impeller to insure the impeller position is not changed. To be certain of the pulley position for your vehicle, install the pump with the gasket and lightly tighten the nuts. Use a straight edge across your lower belt pulley and to the edge of the pump pulley. That will show if the position is correct for your vehicle. Something you do not get with a purchased replacement.

Pardon me for this vanity. This is my press. It was originally one with a handle that had to be fully rotated when operating it. I made the ss handle, ss fulcrum weldment, tool steel ratchet parts, aluminum release ramp, platen, Delrin internal bearings, and added the handle.

06-27-2007, 03:33 PM
Excellent job Tom, and great write-up. I cannot find any flaws in your methods of reassembling the pump. The "seal driver" as you call it it the key to the whole procedure. With a unitized seal, the seal has to be pushed into the housing AND onto the shaft at the same time while retaining stack height. If not done that way, the seal will most likely pull apart and be useless. The only way to do it is with the type of tooling your brother made. I took one look at how high the seal was when placed in the tooling, and knew you had it right. It's been a long time since I put together water pumps, and have forgotten the depth of that tooling, but sure do remember what the seal looked like when placed in there. You might want to give the dimensional data for that tooling in case someone who reads the WIKI page and wants to try this themselves will have that info.

Perhaps you should be the one to offer a rebuilding service for these water pumps. /bcforum/images/%%GRAEMLIN_URL%%/thumbsup.gif

Once again, Great Job!! /bcforum/images/%%GRAEMLIN_URL%%/thirsty.gif

06-27-2007, 05:20 PM
I had an appointment to make and was trying to beat the clock when I posted this. I forgot to give Harold's info and that he would provide the seal driver dimensions depending on the seal choice.

There might even be some spelling errors towards the end because I did not proof all of it.

I will try and do those things sometime this evening.

Art, I almost forgot. Thanks for checking this project over. It is easy to make a mistake or forget something and a secons set of eyes never hurts.

06-27-2007, 11:47 PM
A truly helpful guide! Now I really regret having thrown out an old water pump! And that is an impressive press!

06-28-2007, 11:06 AM

What an excellent process and excellent "How To"
write up. I wish I owned half the tools you do.

I have a water pump question for you.

My new water pump from Moss Motors is due to arrive
tomorrow or Saturday. The Crypt Car currently has
DPO Pedro's water pump that has not YET failed on me.
As we know, it WILL fail and strand me somewhere.

Question: Should I install the new water pump immediately
to verify it is not defective and keep DPO Pedro's as a
backup spare?

Or wait until DPO Pedro's water pump does fail, install
the Moss pump and hope it is not defective?

With the Crypt Car, it is a given that a spare of most
important components must be carried in the trunk due
to frequent breakdowns.

Any idea how reliable the available water pump replacements
might be? I hope they are better than the fuel pumps.



06-28-2007, 11:43 AM
I would check the back side of the pulleys to see if they have any indication of being balanced.

If your new pump does not indicate that it has been balanced, based on what I have learned I would use it for a back up.

If Smiley's (Pedro-with-the-toothy-grin's) pump indicates that it has been balanced it would be a candidate for a rebuild. And it might be one of the good things he did for you. Your new pump could take it's place during that period.

A side note, I also had a conversation with a rep at Gates. I was told to watch their offering of new replacements for a Triumph pump. In the end that might be our long term best solution.