Rebuilding V-8 Flat Head Water Pumps

A

Airrace

Junior Member
Hello:

I was thinking of rebuilding the water pumps in my 1939 Ford Deluxe and was wondering how difficult it is. It is a flathead V-8. I know you can buy the rebuilt kits but, I was wondering if you need to have a press.

Any help or ideas or literature explaining how to do it would be appreciated as I am trying to show my 15 year old boys the proper way of maintaining their grandfathers car.

Thanks in Advance for your help!

Bill
 
I've done it and I'd say the hardest part is preventing damage to the pulleys. I have cast pulleys and cracked two of them (one on removal, one on installation).

I don't have a press, but used my big vise as a horizontal press.
 
Thanks for introducing a young person to the wonderful world of flatheads and old cars. That being said, I would suggest that some things are better off letting the pros do it. I would send the pumps to Skip Haney in Florids for the rebuild. If you want to show the youngins how it's done, get an old pump from someone and have at it. That way if the pulley breaks or anything else, you both learn a valuable lesson. I hope you don't find my comment offensive as it is not intended that way. John
 
flathead4rd said:
Thanks for introducing a young person to the wonderful world of flatheads and old cars. That being said, I would suggest that some things are better off letting the pros do it. I would send the pumps to Skip Haney in Florids for the rebuild. If you want to show the youngins how it's done, get an old pump from someone and have at it. That way if the pulley breaks or anything else, you both learn a valuable lesson. I hope you don't find my comment offensive as it is not intended that way. John
Click to expand...


Thanks for your help. I had a feeling I would need a press.
 
I had never rebuilt a FH water pump. I used Ronnie's instructions and went to a local motorcycle shop to use their Hydraulic press. (I knew the owner). Everything worked well and the pump is still pumping and not shedding water. Byron.
 
I have done several of them. Yes I have broken a couple pulleys too but it was because I was pressing on the outer flange or the whole thing got crooked while pressing. I think it is easier with a press tho. I got some bad gaskets with one set of kits that leaked through them all around the pump. When I took them back off they looked like tissue paper.
 
is there anything wrong with the pumps??...might break off that bolt inside the pump before even getting the pumps off, which means more fun for you and your boys....kudos for you to get them interested and i hope they continue your enjoyment of the old cars....Mike
 
I can do the bushed ones ok, I just push the shaft out the back and leave the pulley in place until the shaft passes through it. In other words I never try and pull the pulley.

Works ok for me.
 
I rebuilt my 34 pumps & broke 2 pulleys, This was before I knew about Skips pumps, if I ever need to do any more pumps I will send them to Skip's plus they will pump more volume than original. Just my 2 cents.
Gary.
 
Airrace Skip has rebuilt and modified thousands of sets of pumps and coils for about 17 years or more and no one has ever been charged for a repair on the few failures that occured in that time. He modifies the pumps to pump more water to cool the engine better. He uses a turbine impeller that no one else has. The stock pumps for a 39 each pump 65 gallons in 5 minutes, after he modifies them they do 110 gallons each. Every pump is tested on a water pump test machine for at least 5 minutes for performance and leaks. The body is also remachined for the turbine impeller which is a more positive pump pumping very little air into the system. This is important because solid water is a mass and cools better then air mixed into the water makeing more volume but not as good for cooling. When new bushings are installed they are pushed into the houseing and the ID changes and must be reamed to the correct clearance with a very sharp reamer so the pores in the oil-lite bushing don't get smeared shut from a dull reamer. There has to be 1/2 thousanths + clearance all the way around the bushing for oil. The shaft runs on a film of oil NOT AGAINST the bushing. When I say oil I'm talking about low temperature, low melting point or low drop point grease. The pumps are greased once or twice a year with 3 or 4 strokes of the grease gun. This grease lays in the pump cavity, melts and sturates the bushing when it gets hot. DO NOT use high temperature grease or keep pumping grease in. This can break the water pump houseing on 32 to 36 pumps where the front curves around to the side, right in the corner. I would say 40 to 50% are cracked and Skip welds them as part of the rebuild. If you pump grease in it will also pump grease through the pump seal into the water. If high temperature grease is used it won't melt into the bushing and if forced into the water coats the block and can plug the radiator and it's 500 degree grease it won't melt at 200. When the shaft fits properly in the bushing you can take your right thumb and middle finger with the shaft through the bushings and feel the shaft slightly wobble in the bushings. Then oil the shaft and bushings and try to wobble it, it's a perfect fit and feels like a bearing. A shaft that is snug and turns hard very seldom loosens up but runs dry and gauls the shaft. I see pump bushings all the time and there is very little wear in them after 50 years. If you decide to do your own try the new shaft in the old bushings and do the wobble test then oil it and if the wobble is gone use the old bushings. You also want to convert your radiator for a 4 lb pressure cap if you don't have one or order a 3 lb pressure valve from Skip. The 39 radiator should have a washer like seat down in the filler neck about 1 1/4" for the pressure cap to seat on. The over flow tube MUST come out of the neck if you use a pressure cap. An over flow tube can be put in the neck and the over flow tube off the radiator tank plugged so it don't work. Or you can use the 3 lb pressure valve on the bottom end of the over flow tube. The pressure cap or valve is required for better cooling, without one of them the water backs out the over flow tube then the radiator has 17 quarts instead of 22 so the engine will run hotter because it's low on water. Three things to improve cooing of these engines are more water, more water flow or more air flow through the radiator. Any one will make an improvement and all three put it at it's max. Disreguard the grease part for your pumps, this applies for 32 to 36 pumps but I will leave it in this post for others. Your pumps are lubricated by engine oil that enters the pump from a small hole in the mounting surface of the pumps. This oil is not pressureized but is a drip flow. Follow the instructions and do not use silicon sealant or you could plug the oil holes. The mounting surfaces of the pumps are resurfaced so just put a thin coat of grease on both sides of the new gaskets that come with the pumps. Replace the bolt in the lower hose connection with a SS bolt OF THE SAME LENGTH. one to long will bottom out and not tighten the pump against the gasket. G.M.
 
Last edited:
Great info G.M. I really appreciate when experts like you and others like Mac VP share valuable info like this. Even though you have a product or process to sell, it is refreshing to hear the rare details known to few.

Lonnie
 
Lonnie, I don't have products of my own to sell. I helped Skip develope and test his products a number of years ago and assist him if he has a problem. I don't receive the checks or pay the bills. Skip worked for me for years before going into rebuilding the parts he does. I let him use my machine shop for the pumps and he does the coils at his shop at home. In return he looks after my home and other properties in Fl. when I'm in Pa.and helps me for a few minutes if I need help. I just have fun with my old Fords and working on my projects such as dual tanks and better fuel milage on my Duramax. I got the mileage up from 18.3 to 21,7 on trips and a range of over 1,000 miles, it's running smooth and I'm happy with it. I'm testing another product for someone else right now which looks good and when I'm done and this person is ready to be able to deliver the product I'll post a report. This is something we have been looking for for years. G.M.
 
My mistake. By your descriptive knowledge of the process, I thought you were Skip with a pseudo handle. Sounds like you're paying it forward by helping others. That's good.

Lonnie
 
You must log in or register to reply here.
Back
Top