Bob's 26 Buick water pump rebuilt kit

[Old26Buick]

Has anyone used Bob's WPK-260 water pump rebuilt kit ? I can't seem to get my packing from leaking. looks like shaft is worn. thanks for any help

[Mark Shaw]

Typically after sitting for a long time, the shaft will be pitted & will not allow the packing to set. The solution is the replace it with a SS shaft.

[Old26Buick]

Mark, Do you know if Bob's Kit has a stainless steel shaft. I have a machine shop that could make one. Thanks

You probably don't remember but I meet you at the National Buick meet 2 years and had my 27 Buick woodie.

Steve Smith

Falmouth, Me

[AzBob]

I purchased Bob's kit for a 1926 standard six and noted a few minor differences. The impeller had slightly thicker vanes and was a rougher casting than the original, the shaft was machined from soft steel, original was hardened steel. The gland packing nut had tool chatter marks on the hex nut portion. Haven't had a chance to do a functional test yet as the generator is out for rebuilding.

In addition, you will need a means to press in the bearings without damaging them as they are a press fit.

Edited February 4, 2015 by AzBob
additional information (see edit history)

[Larry Schramm]

I am getting a stainless water pump shaft made for my truck. If anyone needs a shaft made, I have a machinist that can make one. Just need the old shaft for a pattern.

[tonybuick]

hi is stainless steel the right metal to use I know it won't rust with the water but doesn't the bronze stick to it or gets torn by the stainless steel shaft

[hidden_hunter]

that's disappointing to read, I was looking at getting the kit as mine drips fairly badly and the impeller has seen better days

[Larry Schramm]

hi is stainless steel the right metal to use I know it won't rust with the water but doesn't the bronze stick to it or gets torn by the stainless steel shaft

With the new lip seals so it does not drip like packing, I am going to put in coolant that contains a lubricant and all of the other additives to keep the cooling system from rusting, etc. I do not believe that there should be a problem.

[dibarlaw]

I have been looking for a 1925 Standard water pump (no rebuild kits available) to make a new shaft / impeller build up etc. Mine is pretty scored up and I have not attempted removal. I just squeeze more packing in. I have plenty of good tips from Leif but I would rather have something in hand before I will tackle this job. In case I do some damage.

Larry

[Jim Bourque]

Larry

I have this pump that is marked 25 standard that I have no need for as my car is a 25 Master. Impeller diameter appears to be

3 1/2 inches and 4 bolts that hold it together. If it looks like what you need, it's yours for shipping cost. Pictures attached (I hope)

Jim Bourque

[dibarlaw]

Jim:

Thank you for the response. It is really something about the differences between Standard and Master components. I see that the shaft was cut and there is only about 1/2 left. The packing gland nuts I can machine and cut the right and left handed threads. Mine are pretty mashed up. I was hoping I could find a complete shaft to directly fabricate a new one from the old. But beggars can't be choosers. At least I could make up new bushings, seals etc. I am trying to accumulate needed parts when the time for a rebuild occurs. My engine is quite tired. The fellow I purchased the car from said that there was a complete engine and other spare parts that was to go with it when he bought it around 2000. He said the former owner passed away before he could ship the parts. And all were tied up in the estate.(Good story since he could not remember the fellows name or where he bought it from). I will send a PM with my address. Let me know what the shipping is plus something for your trouble.

Thanks again:

Larry

[Jim Bourque]

Larry

I may have some gland nuts that will work if they are the same as the Master 6. If it was my car I would make a stainless steel shaft and a coupler sleeve to attach to existing shaft. Morse taper pins to attach.

Jim

[tonybuick]

hi make the shaft in two parts and make a coupling for it. it makes it quick and easy to remove if you need to service the pump or starter generator unit use a key in the coupling which is as long as the coupling sleeve and slot the two shafts I could supply more pictures if interested tony

[tblack]

hi make the shaft in two parts and make a coupling for it. it makes it quick and easy to remove if you need to service the pump or starter generator unit use a key in the coupling which is as long as the coupling sleeve and slot the two shafts I could supply more pictures if interested tony [ATTACH=CONFIG]294348[/ATTACH][/QUAgeOTE]

I agree ..I did this same thing on my 22 buick parts engine

[hidden_hunter]

hi make the shaft in two parts and make a coupling for it. it makes it quick and easy to remove if you need to service the pump or starter generator unit use a key in the coupling which is as long as the coupling sleeve and slot the two shafts I could supply more pictures if interested tony [ATTACH=CONFIG]294348[/ATTACH]

is that for a 26 master? with the 26 standard you just unbolt the top of it, slide it back and remove the bakerlight plug and it lifts out after a bit of manoeuvring

[tonybuick]

no its 1925 buick standard use the coupling on 1925 or older that used a starter generator it helps to get the water pump of it can be a bit of a dog to get off 26 changed and used a different set up

[26-25Buick]

Time to weigh in to the discussion with a bit of metallurgy and corrosion theory.

Ok why is as AzBob reports the original Buick shaft hardened as hardening in most cases won't improve corrosion resistance, well certainly the hardening processes in 1926 would not have. My guess, and anyone chime in if they have another theory, Buick was trying to improve the erosion resistance of the shaft both from solids in the cooling water like rust, dirt, etc and from any cavitation caused by the impeller. Hardening also helps with fatigue however I think you can rule out fatigue as there is very little load on this shaft. So will the non-hardened shaft in the WPK-260 kit work just as well as the original one, from a corrosion perspective for most of us yes, as the water quality today is significantly better and we can control the water chemistry with inhibitors so rust and erosion in the system is less of an issue.

If you're contemplating using a stainless steel shaft think very carefully, while most of the issues can be controlled get it wrong and it will go bad very quickly.

The most obvious issue is carbon steel is anodic to stainless i.e. the carbon steel will corrode if it's near the stainless like for instance the internals of the pump casing or near the gland nut, in fact using a stainless shaft may actually increase corrosion in the pump casing. Keep in mind that corrosion rates increase with temperature in the temperature ranges we are talking about here, so the more you use the car the worse the problem gets.

The next issue is the most common types of stainless work great where there is oxygen available however if you have a crevice say where the bearing is pressed on or perhaps at the gland packing or you use a corrosion inhibitor which contains an oxygen scavenger it will pit as bad, if not worse than, everyday carbon steel as there is no oxygen to form or maintain the passivisation layer.

The final thing to think about is one of most common free machining stainless steels is 316L and its used in lots of things from cookware to nuts and bolts because it is so easy to machine in to shafts and draw and roll in to shapes. The problem with it is it is prone to crack in temperatures around 150F and above in the presence of chlorides or sulphides. So you need to know what's in your rad water and any additives you are thinking of using because you are certainly operating in the crack initiating temperature range.

Sorry for for rather long and technical response guys and girls

[DonMicheletti]

The original pump shafts are case hardened for one reason.. to resist wear from the pump packing. Overtightening is a very typical problem on all packed pumps. When I was working in a chemical plant that had lots of packed pumps, shaft wear under overtightened packing was called "mechanics art" and really common.

Actually, stainless steel isn't a good pump shaft material at all. It is relatively soft and will quickly groove if packing is overtightened. You have to be careful when tightening gland nuts on a stainless shaft.

However, I replaced the original corroded and scored shaft on my '18 Buick about 40 years ago and it is still OK and doesn't leak a drop. So stainless does work if you are careful about tightening the packing nuts.

[Larry Schramm]

Here is going to be my "packing" for my new water pump shaft in stainless steel.

http://www.mcmaster.com/#13125k92/=vvos6w

Anyone see a reason that it should not work?

[DonMicheletti]

It will be interesting to see how that works out. The specs say it should work.

I wonder if it will eventually wear a ring in the stainless shaft? There is virtually no water pressure and the Buick isnt exactly a high speed application.

[Mark Shaw]

Larry,

IMO, installing lip seals isn't justified. I suggest using graphite impregnated pump packing with a new shaft in the original packing gland with very little water resistant grease (the kind used for boat trailer axles).

However, the seal you selected will work as long as you have your Buick. As 26-25Buick said, stainless also has it's limitations (I do wish we could all use our real names). Teflon packing does tend to groove stainless shafts when it is over-tightened. I do not agree with the crevice corrosion & anodic issues listed above when used with modern anti-freeze that has anti-corrosion additives.

I sold industrial chemical pumps and valves for over 28 years, & learned that all machines used in corrosive or chemical services are designed with a corrosion allowance. Centrifugal pumps can typically handle much more corrosion due to the large tolerances in their design. But valves tend to be much more sensitive to corrosion due to the close tolerances required to attain tight shut-off. Just take a look at the pump body in your Buick. I think you will see there is plenty of material left after all the corrosion of 90+ years to handle another few decades...

Edited February 13, 2015 by Mark Shaw (see edit history)

[Larry Schramm]

Mark,

Prior to my purchase, someone left water in the pump and it froze. It has been completely reworked/ repaired. I hope to get rid of the dripping. Worse case, re-machine it and put packing in it again.

[DonMicheletti]

I have to go along with Mark. Done right, the original packing setup will work perfectly for a long time. The key word is "right".

The good news is that we all get to do what we want!

[Dandy Dave]

I have a Stainless Shaft in the 1915 Buick. Has been in service for about 8 years. One thing I have learned, no matter what you do, nothing is forever. Someday the earth will be incinerated by the sun and then recycled by a new universe. Everything will eventually go back to it former state. I would say the big question is, How many years would a new shaft last, and should we worry that it may fail in the next hundred Years? I won't be around to worry about it. Now, for the Next Generation... Dandy Dave!

[Brian_Heil]

My pump shaft is worn down to about 75% remaining diameter, looks like the Moon and has enough miles on it to have worn the clutch pedal smooth, no tread, so no guess as to the miles on it but it has to be a bunch. Remember this sentence.

My pump didn't leak 18 years ago when I bought the car until I messed with the packing nuts and pulled out the packing (look at all this old crap in here, where's the trash can, I need to 'fix' and replace this nasty business). On one end there was a leather boot lace in there. I can just see the old farmer with the flopping boot and the smirk as he motored away with the leak fixed, wife and kids telling him how great he was.

My pump leaked like heck with the modern packing material I found and packed in there. (Get a bigger wrench and tighten that nut some more . . . nope)

My pump stopped leaking about 20K miles and 15 years ago when I bought the proper graphite impregnated packing material from Restoration Supply Co. based on comments from a fellow Buick Tourist. Cost me a couple of bucks. Still got most of it left under the front seat in a zip lock bag.

(Mrs. Flath would give me a D+ for starting all these sentences with 'My'.)

I very much enjoyed the discussion above on corrosion. I find no errors.

Modern 50/50 coolant is wonderful stuff. Good lubricity, anti corrosion and not much loss in specific heat (ability to 'carry' heat compared to plain water).

The money I saved on not having a shaft made I spent on important stuff like new brake bands and beer with some of the wonderful people on this site. No disrespect to anyone who can machine or get a shaft machined and replaced. I've seen several that are works of art. Try the correct packing route first, it worked for me.

[26-25Buick]

Good point Don, I hadn't thought of the hardening being also for the purpose of the gland nut.

Being in the corrosion business for over 30 years you see stainless being over specified and used in so many places it should never have been used. Don't get me wrong, in the right place it can't be beaten but buyer be ware like everything, it has its limitations.

By the way my hats off to all who actively participate in this forum as the knowledge, experience and opinions you share are invaluable. I have learnt a lot in a very short time.