fairbanks morse model 41

tuneup

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Recently we removed an old stationary well pump from my mother home 1900 era.
It is a Fairbanks Morse model 41 connected to a swallow well. It hasn't been used for years, but was our water supply some 60 years ago.
It has casted on it "A 250 Fairbanks Morse model 41 ". the 250 is a stamped number made on a flat plate in the sentence.
this is a motor driven pump that has the motor mounted above it and the horizontal pump below connected with a v-belt.
It seems to have a flat or loose spot on the connecting rod in the transmission that is loose between the push to the pull transition of it's motion.
Before I take it apart, I would like to find any information that might be available or anyone with experience.
Is't a neat little pump!, I don't want to mess it up!
it has the original motor and much of the green paint is still on the pump housing.
any help would be greatly apreciated.
thanks in advance
Rex

I hope this isn't getting posted twice, I'm having difficulties with the posting!
 
I would love to see a photo. I have a 1912 FM Eclipse pump engine that runs well.
Richard in NW SC
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Yesterday, I was able to break loose some of the rusted and corroded connection of the pump body. It has lost of calcified deposits that cover everything the water has touched and could evaporate. The piston mechanism has some sort of packing or sealing material under a screw on cap. It's hard to get at and a special curved wrench with a plug on it that will fit into a hole is needed. I don't know what it's called, but I have saw one before. I think it might be called a spanner wrench, but I don't have one.
There is only one connecting bolt that holds the top to the bottom. It broke loose from, who know how many years, of connection. It broke loose and came out.
Taking the top and bottom apart wasn't quite so easy. But I got it done. it will need new gaskets but they look quite easy to make. The valves between the top and the bottom were completely frozen up and would not work. It was as if they had been glued shut!
The insides were almost completely packed with rust!! It's a wonder the piston could even move. I pulled about 2 cups of dried rust out that had accumulated over all this time.
This pump has for chambers. On top there are two chambers, splitting it from side to side. On the bottom half there are also two, but they are splitting it front to back.
Water enters the inlet at the bottom and travels through a screen and passage to the right side of the top chamber. This is over both the front and back of the two bottom chambers. The top and bottom are separated by four one way valves allowing water to go down only on the right side and up only on the left side.One down valve and one up valve for the bottom front and the same for the bottom back section.
As the piston moves, water is drawn into one of the bottom chambers from the right top chamber through one of the check valves.
Once in the bottom, the water can move from the right side to the left because the bottom chambers is under both right and left ides of the top of the pump. The same for the other bottom chamber on the back of the pump.
Now when the piston returns, it compresses the water forcing it through a second check valve up to the top of the pump, but this time on the left side. The left side is connected to the outlet of the pump.
The bottom back side does the same thing as the front,but it's in the compression stroke while the front in in the suction stroke of the piston. The piston both compresses and vacuums at the same time with every stroke. it uses both end of the piston as if it were two cylinders back to back.
so when the piston moves forward, it forces water out through the front chamber and when it returns back again, it forces water out through the back chamber. two pumping actions with each stroke.
Pretty ingenious!

If anyone has tips on how to go about any of this work, I would love to hear from you.
Have a great day.
Rex
 
I signed up just to reply as I have the same fair banks pump that I never found any information on in years! I will try to post some pics. Also I went through the entire Pump blind and may have some advice. I can tell you it pumps very well.
 
Love your pump.
mine looks the same, but in great need of restoring. It is missing the bottom stand, it was almost completely corroded away with only the slightest resemblance of yours. and defiantly not the emblem your has at the bottom.
Also the tube sticking out from the piston area, what is that and what is it's purpose. Mine was corroded back to the threads.
one last major difference, the plug in the side is were my outlet was connected, and the longest horizontal tub on yours had some sort of a unit that I thought might be a shock absorber of some type. it had a valve stem on the end of it.
Thanks for your photo, it speaks a lot of what I can do to restore it.
Thanks again,
Rex
 
Nice to know that I'm not alone in researching without results!
Your past experience with this pump would be so valuable. I don't whant to have to rediscover what has already been known. Any advice you could share would be greatly appreciated.
Thanks Rex
 
The tiny horizontal tube in the middle of the pump just drains water that collects in the center of the pump. After the cup leathers expand on the piston it generally wont leak as much. The pump also has a Schrader valve on the side like a bicycle tire has, it is used to "release air and pressure" from the system. I left mine there as it will release air when pumping water, of course you do it manually.
Yes you will have to make gaskets for the main head, I used rubber/cork and an xacto knife and alot of patients. Leather cups for the piston I purchased from Dean Bennett supply, I can get the size but i do remember they were solid center leather cups which i used a punch to make a center hole. As for the rubber gaskets in the pump diaphragm, I did get the correct diameter and inner diameter from Home Depot but the thickness was never correct. So i used two for each one on the pump. That brass diaphragm also has spring on each rubber washer, hope yours are still there
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