OP
955Lincoln
Gold Member
That's right, your wording threw me off. The fuel comes out the top of the tank through probably a coarse filter, to the scew-on replaceable filter, fuel pump, and then to the injector pump.
Old Fuel in Diesel Tractor
- Thread starter 955Lincoln
- Start date
- Views: 8942
denchen
Gold Member
I do not know your engine, but. The lift pump or fuel pump or diaphram pump, same thing but different names is often the first pump in the diesel fuel system. What you need to know, Firstly, if you have one, it will be most likely be driven by a lever resting on a cam in the engine. They useally have a priming lever on the outside for manual priming. Now if the engine happens to stop with the lever inside of the engine on the high side of the cam, the lever on the outside will feel as if it is not doing anything. The cam will be holding the pump on its travel stop. The answer, is to crank the engine one revolution, or there abouts, and hope it stops this time on the bottom of the cam, this will allow the lever on the outside to do a full up and down stroke, and pump fuel. Next, these pumps often are a diaphram pump, in that there is a rubber/ cloth fibre diaphram, and the cam/ primer lever pushes this diaphram up and down, so pumping fuel. These diaphrams after use sometimes get a tiny hole in them that lets fuel leak through, and if the motor has been stopped a long while will allow air into the system. And, sometimes these pumps have a course gause filter within the pump. If they fill with crud then they do not work properly. Good news, often you can get a repair kit or just the diaphram, and they are fairly easy to fix.
OP
955Lincoln
Gold Member
I have a lifetime of engine experience but lacking knowledge of diesel fuel age problems. The pump is a diaphragm and I tried the priming lever in many different engine positions. Earlier in the thread I mentioned hearing slight air noises coming from the air filter while pushing the primer lever. I have never had an injector pump apart but I'm guessing the air was going through the pump (if this can even happen), out an injector, and through an open air intake valve(s).
OP
955Lincoln
Gold Member
I have pushed primer levers before and in this case there was no resistance other than the diaphragm spring. I pushed it as fast as my finger would move with no push back. I probably shouldn't have mentioned the air because it was not more than a gnat fart. The only reason I heard it is my ear was right at the air intake.
denchen
Gold Member
So the primer lever is moving with no resistance. This I guess is because the pumps diaphram is full and the pumps return spring is holding the diaphram. Is it possible to loosen the outlet of the pump. A little diesel should come out from the pressure from the spring, and then the lever should work and push more fuel through. If the lever is still moving with no resistance, then it would seem there is a vacuum between the pump and the tank. Crud, and is there one of those small filters at the end of the pipe that goes into the tank. Years ago some diaphram pumps had a small gauze filter where the pipe from the tank went into the pump, but I hav'nt seen one of these for years.
Jerry/MT
Elite Member
- Joined
- Feb 2, 2008
- Messages
- 3,140
- Location
- North Idaho-The Palouse
- Tractor
- New Holland TD95D, Ford 4610 & Kubota M4500
My 2007 NH TD95D has the screen in the mechanical lift pump.
OP
955Lincoln
Gold Member
I'm guessing the tank pipe would have a filter but the parts diagram just shows the top mounting plate and a short portion of the pipe for compactness reasons. I would say it feels more like a vacuum between the tank/filter and pump. There is a return line to the tank and I would think that the primer should always flow fuel even if it's going back into the tank.
I think the problem will show up quickly when I return with tools and a new main filter.