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water pump part 2, inspecting and measuring

tomshobby

Yoda
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Hoping this is not to boring. I will try to finish the assembly part yet this week.

It is a good idea to look things over during disassembly to see if there are any obvious problems. Things like a cracked or broken pulley, housing, or impeller. Also look over the bores for obvious wear and be sure and include the housing bore for the seal flange. Check your pulley groves for excessive wear also. Check for signs of a coolant leak, even if small. It might answer other questions you have had.

The drilled holes on the rear of the pulley are to balance it for longer bearing life and to reduce fatigue in the shaft so it does not break. It would be rare for a pulley to balance with none of these holes.
pulley_10.jpg


Evidence that the seal was leaking. Probably becoming noticeable on the front of the engine.
housing.jpg


A couple of photos showing the housing a little cleaner. The side hole from the bore to the outside of the housing is for liquid to escape without getting into the bearing. The pump must be installed with this hole to the bottom.
cln_housing_01.jpg


cln_housing_02.jpg


Assuming your pulley, hub, and impeller are in good condition the next thing is to take a few measurements. I first measured my bearing/shaft so I would have the information to identify the correct series for the replacement.

My bearing /shaft had the following dimensions.
The bearing diameter was 1.181” or 30mm. (Standard size)
The bearing length was 1.528” or 38.8mm. (Standard size)
The shaft diameter was .6265” or 15.918mm (Standard size)
The overall shaft length was 4.4125”
The vane end shaft was 1.836”
The pulley end shaft was 1.0615”

Then I measured the bores for the shafts and bearing. These are the most important measurements you will take, if you do not feel comfortable with your skill level here have someone take these measurements that is. Especially in the pulley and impeller. I wanted .001” to .002” interference fit between them and the shaft. In other words the bores should be slightly smaller than the shaft. That is what keeps them together. Too little and the pulley or impeller might slip or spin, or worse just come off the shaft. Too much and they could be stressed to a point that at high RPMS they might hatch (come apart due to centrifugal force and stress) Knowing the bore sizes makes it possible to order a bearing with a correct shaft size.

One more bore to measure is the one for the seal flange. Because it is a standard size bore it is not nearly as critical as the others but you do not want to be sloppy either.

I did a lot of searching and finally found John Crane, Inc, which is a company that produces seals. I talked at length to one of their technical reps, who recommend one of their seals, S106MAST, a ceramic seal with stainless components. He also recommended the Harold Bishop’s HDRK CO, INC. IN Albany, Indiana. (765) 789-4406. I called Harold and gave him the measurements I made 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.

You might notice the shaft lengths are slightly different than the original. You will see how to deal with that in the assembly part of this series of posts.

The old and new shafts. Notice the rust on the vane end of the old bearing. Not only was it failing but it could have possibly been avoided. Look at the new shaft and it has a groove around the shaft near the bearing. That groove will throw the coolant off and prevent it from following the shaft to the bearing.
brng-shft_01.jpg

brng-shft_02.jpg


The new seal
new_seal_01.jpg

new_seal_02.jpg


Following are a few measuring tools that might be used on a project like this and a little about using a caliper. Calipers, especially dial calipers, are quite inexpensive and even available in the $20 range. As handy as they are it seems to me to be an essential tool.
This picture shows 1” to 2” and a 0” to 1” micrometers and a set of inside micrometers. These are generally used when a more accurate measurement in the range of as little as + or - .001” might be desired.
meas_tools_01.jpg


This picture shows a digital caliper, a set of telescoping gages, and two sets of feeler gages. The telescoping gages are what are called transfer measuring tools. What that means is that they are set to fit the inside of a bore or groove and then removed and measured with a tool such as a micrometer or, less commonly, a caliper.
meas_tools_02.jpg


A caliper could be a vernier, dial, or digital variety. The dial and digital are most commonly used. One of the most important things to remember when using a caliper is after making and recording a measurement to close the calipers to make certain it is still reads zero when closed. If it does not read zero the previous measurement may be invalid. It is also important for the jaws to be clean when setting the zero. One of the best and easiest ways to do this is to simply close the jaws on a clean piece of paper and draw it out while keeping a slight pressure on the jaws. A caliper is generally not reliably accurate to less than + or - .002 and then only if it is in excellent condition. The old one in the pictures is not that good. Because of that I am careful what I use it for.

Here are the four ways to measure with a caliper. It was interesting trying to hold the caliper while taking pictures and even though it may not be obvious, it is important to keep the caliper as square and perpendicular as possible when measuring.
caliper_03.jpg


caliper_04.jpg


caliper_02.jpg


caliper_05.jpg
 
Terrific write-up Tom...looks like you have everything under control. When you're done with all of this, it's definetly a candidate for the WIKI!

BTW, Crane sent you to the right person. I haven't talked to Harold Bishop in about twenty years. (As long as I've been out of the water pump business). Good to here he's still around. I used to buy a lot of component parts from him. He also supplied his customers with drawings and dimensional data for all the pumps. He is a wealth of knowledge. He's the "H" in HdrK Co. The "drK" part was his partner Donald R. Kelley...(no typo here..."dr" is supposed to be in lower case.)

Anyway, I've been following your project, and you've really done you're homework. Looking forward to the last installment. /bcforum/images/%%GRAEMLIN_URL%%/thirsty.gif

Edit: Being that you have a standard size shaft on the bearing, I would use a little loctite on the pulley and impeller. Also, use some thin permatex or even a bead loctite on the cartridge part of the seal when you press it into the housing.
 
Thanks Art, it is good to know someone that knows this material is checking it over. Thanks, Tom

I just placed the first two on the WIKI and made a place for the third. I am going to try and get it done before the coming weekend is over. The pump has been together for a couple days and the pictures have been taken.

I just hope someone gets some help from it.
 
Good solid info, Tom!

...I admire your discipline to STOP what you're doing and take photos!
I was gonna give you grief over the set of Mitutoyo's but then remembered: I have a Mitu 0.02"~1.0" I.D. mic. /bcforum/images/%%GRAEMLIN_URL%%/devilgrin.gif

All the rest are Starrett or P&W... calipers are too "general" IMO. You disclaimer'd it well. I've an NSK set but rely on micrometers for most all measurements. Engine work particularly.

Wiki-wiki!!! /bcforum/images/%%GRAEMLIN_URL%%/thumbsup.gif
 
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]I've an NSK set but rely on micrometers for most all measurements. Engine work particularly.
[/QUOTE]

That's why you're the "Doc"!
 
Thanks for sharing the work, it will stay in my keep files.

I can't waite for you to start up on the fuel pump. /bcforum/images/%%GRAEMLIN_URL%%/smile.gif
 
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