'39 commander water pump leak

[fh4ever]

hi all, my '39 has been leaking coolant at the water pump grease cup and not at the packing nut.  I did a search and it seems others have had this issue as well (on other models with slightly different configurations) and the reply normally is "tighten the packing nut" or "time to rebuild".    Can I get your thoughts or experience on this? 

 

Being analytical, I have come up with my own conclusions why coolant leaks thru the grease cup.  Feel free to chime in.  

Looking at the parts diagram, I see packing and nut on one side of the shaft bushing... but only a thrust washer on the coolant side of the shaft bushing.  It appears to me the only way coolant can get into the grease passageway is first, it must seep past the thrust washer.  Then it can escape thru clearance in the bushing and shaft, and eventually reaching the grease passageway in the bushing... thus finding its way out thru the grease cup. 

I can see this happening if.... the packing nut is too loose to pull the thrust washer against the bushing face for good face sealing;   or if there is excessive wear in the mating faces of the thrust washer and bushing;  and lastly, too much clearance in the bushing and shaft from wear can allow the coolant to escape much easier.   

It seems to me the thrust washer to bushing design is prone to some leakage.  But with grease pushed into the bushing clearances, it can help with the final sealing.

I think I will try to tighten the packing nut and try more turns of the grease cup cap to get more grease into it and see what happens.  Or tell me if.... once you see coolant at the grease cup, it really is time to rebuild?  

         

 

[George Rohrbach]

I have a 1939 Studebaker Commander NOS shaft with impeller, front and rear bushing and packing nut available. I do not have a Thrust Washer, although it is available on the web. Contact me if interested.

Also have water pump parts and rebuild kits for other year antique Studebakers.

George Rohrbach

Edited September 20 by George Rohrbach (see edit history)

[fh4ever]

George....PM sent. 

 

Studying up on this more....should I use NLGI  no. 2 or NLGI no. 4?  Both are water pump greases...no. 4 being thicker.  Both of these are water repellent.   

I saw somewhere on the web that water soluble grease was preferred so as not to clog the radiator, the coolant passages, or thermostat if it were to get thru the pump.  Now I am starting to overthink this.... 

Can anyone tell me what did Studebaker recommend in '39 ?   or suggest which grease should be used?   I cannot find this information anywhere in my resource books.  

[George Rohrbach]

I have always used McKay 421. It just says Water Pump Grease. Nothing special about that particular brand, I bought a couple of cans, when the local auto parts store, still carried water pump grease. 

Sorry, I don't know anything about the specifications for it.

George Rohrbach

[George Rohrbach]

I thought that someone else might like to see the page from the Manual of Step by Step Service Operations, that was a Supplement to the 1939 1940 Commander and President Shop Manual, for water pump repairs.

George Rohrbach