repair of HD3 Allis fuel purge hand pump

Forum,
Has any one tried to repair a fuel purge pump on an HD3 Allis or any equipment with said pump. I believe it is a diaphragm type pump. Being 1965 vintage it seems to not pump as in the past. Any and all info is appreciated.
 
I don't know about the HD3, but, as I recall, other AC's of the era used the little Roosa Master primer with the little wire bail
and nut which is flipped down to allow the piston to move. That piston will come out, and there's a rubber piece on the end. That's
as far as I've ever been into one. If it really won't pump, I'd sooner think there's a fuel restriction before the pump.
 
An old parts book I got for the HD3 shows the hand priming pump to be the plunger type not diaphragm, the pump consists of a plunger, two valves, spring and seals, there is not a collective number for a repair kit, if it is not working right more than likely one of the valves is either damaged or something holding one off it's seat, if there is a fuel injection shop near you drop it to them to repair it for you would be the best bet as they would have spares.
AJ
 
(quoted from post at 01:07:52 06/01/21) Forum,
Has any one tried to repair a fuel purge pump on an HD3 Allis or any equipment with said pump. I believe it is a diaphragm type pump. Being 1965 vintage it seems to not pump as in the past. Any and all info is appreciated.

Thanks for the replies. The pump did work when I first purchased the HD3 four years ago. Then it became intermittent in operating. Flow of fuel from tank to bowl is open and flow from filters to injector pump is open. I will open the plunger pump up the next time I head to the cabin. Seems another diesel I have is a lot simpler when it comes to filters and fuel from tank to injector pump. Will keep you posted on future progress.
 
A scan of the parts book page if it comes out, don't see to be having much luck uploading a readable copy.
AJ
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I have an HD-3. I have always been able to gravity bleed it if the fuel tank was pretty full. Just open bleeders and wait for fuel
to run out the close them . Once it is bled to the pump if you need to bleed to injectors you have to do that the normal way.
 
(quoted from post at 15:27:36 06/02/21) I have an HD-3. I have always been able to gravity bleed it if the fuel tank was pretty full. Just open bleeders and wait for fuel
to run out the close them . Once it is bled to the pump if you need to bleed to injectors you have to do that the normal way.

I will try that. After the experience of molasses like gunk in the tank last summer I am a little hesitant to fill the tank. Currently there is a minimum amount of fuel in the tank till I get it going again. Thanks
 
You may want to rinse the tank out, maybe add a couple gallons of fuel and use compressed air to stir it up and drain into a
container and see what you get.
 
If it becomes too hard to make this primary pump function right you can always install a little 12v pump and be done. The reason they even have a primary pump on the HD3 is for working on slopes where gravity is not enough to supply the fuel to the injector pump. With two of my Allis backhoes I just ran gravity feed and eliminated the primary pump. If I knew I would be working on steep inclines I made sure the fuel level was high in the tank. I never had a problem.
 
(quoted from post at 01:08:38 06/03/21) If it becomes too hard to make this primary pump function right you can always install a little 12v pump and be done. The reason they even have a primary pump on the HD3 is for working on slopes where gravity is not enough to supply the fuel to the injector pump. With two of my Allis backhoes I just ran gravity feed and eliminated the primary pump. If I knew I would be working on steep inclines I made sure the fuel level was high in the tank. I never had a problem.

I bought a 12 volt fuel pump and was attempting to prime the system last summer. It worked quite well to force/pump fuel into the system. Thinking of placing the pump between the sediment bowl and the filters. Would that be a good location? Do not know if you have been following this story since last summer but the HD3 ran very well before the gunk developed in the tank and worked its way to the injectors. When I travel north next I will be tackling the hand pump and cleaning the gunk clogged injectors. It has been a learning experience. Will keep the forum posted on progress.
 
Yes, between the sediment bowl and the filters would be the right location for your 12v pump. I do remember following your thread earlier with your fuel troubles. Are you sure the injectors have gunk in them? How would it have got past the filters? Usually if the filters plug up no fuel comes through.
 
(quoted from post at 05:17:02 06/03/21) Yes, between the sediment bowl and the filters would be the right location for your 12v pump. I do remember following your thread earlier with your fuel troubles. Are you sure the injectors have gunk in them? How would it have got past the filters? Usually if the filters plug up no fuel comes through.

How do I know the gunk got past the filters! Well, this gunk is a mold type growth that permeates the system and got past the filters. Hind sight tells me I should have used a treatment in the fuel to treat the "new" lower sulfate diesel fuel. The treatment is in the system now and may clean up the what I believe are mold clogged injectors. Hind sight also tells me if I would have known what is was to begin with I would not have run the HD3 last summer which allowed the mold/gunk into the injector pump and injectors. I did replace the fuel filters which looked fine. I also cleaned the injector pump which was not allowing fuel to travel through. Cleaning the injector pump took Sea Foam and patience. The last step is to clean the injectors which have fuel available but not allowing the fuel through? Appreciate your question and hope I answered it. If the HD3 was in my yard and not 170 miles away would also help!!
 
Not easy for you to just go out and try something with the tractor been so far away, when diesel waxes up it will do it through out the system, it does not wax up in the tank first and then travel through the system, it is more likely to wax up in the filters first and the fuel lines as the material is thinner than in the fuel tank, if you are doubting the priming pump could you flush it out where it is, the engine will run without that pump working, inside the injector pump there is another small pump referred to as a transfer pump, it's job is to pull fuel from the tank through the sediment bowl, priming pump, filters into the injector pump where it is pumped on under pressure to lubricate the I/P and supply the hydraulic head and return to the tank, that priming pump make bleeding easy.
Good luck
AJ
 
(quoted from post at 21:55:56 06/05/21) Not easy for you to just go out and try something with the tractor been so far away, when diesel waxes up it will do it through out the system, it does not wax up in the tank first and then travel through the system, it is more likely to wax up in the filters first and the fuel lines as the material is thinner than in the fuel tank, if you are doubting the priming pump could you flush it out where it is, the engine will run without that pump working, inside the injector pump there is another small pump referred to as a transfer pump, it's job is to pull fuel from the tank through the sediment bowl, priming pump, filters into the injector pump where it is pumped on under pressure to lubricate the I/P and supply the hydraulic head and return to the tank, that priming pump make bleeding easy.
Good luck
AJ

Thanks for the input. The reason I figured "waxed fuel" got transferred to the system is the HD3 ran fine the day I realized there was a suspicious substance in the tank. Have you ever encountered this so called waxed gunk? I researched many sites and finally found one that matched the brown molasses like substance I had. When it drys/cures it is/was like brown gasket making adhesive!! One thing I know for sure is acetone cuts it quite well. Thanks again for the input. Will keep you posted.
 
I am in the heavy equipment repair business and have seen the problem you are having many times, the fuel turning to a reddish black I am led to believe is a chemical reaction in extreme cold conditions, like if tar was added to the fuel and it sets rock solid, Acetone is very good for getting rid of it and also very good for cleaning the carbon from the injectors.
AJ
 

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