Fuel Pump Quit

countrysquire

countrysquire

Senior Member
I've been working on getting my long dormant '40 running and have finally solved my ignition problem (another thread) after much troubleshooting. So Thursday I show my wife how it starts instantly now that it has plenty of juice to the plugs, but it didn't start. Fortunately, the transparent red hoses going to the freshly rebuilt (by Charlie NY) carbs let me see that there was no gasoline coming from the pump to the carbs. I pulled the top off the pump to see if the screen was plugged and noticed that the 'rubber' gasket had probably tripled in size since I rebuilt the pump a few months ago. After putting it back together, it pumped again and ran wonderfully. Went to start it yesterday and found no love as the fuel lines were empty again. After coming inside to watch football and drink beer, I stewed on it a bit and figured that the diaphragm had grown like the gasket and wasn't pumping any more.

So, this morning I took the fuel pump off and opened it up. The diaphragm looked ok, but I swapped to another fuel pump (a very old rebuild with the Ford rebuild ribbon) but there was no change. When mounting the stand on the intake, you can hear the pump move and suck/blow. I didn't measure the travel of the pushrod, but it looked sufficient. I tried several things to get it to pump but had no luck.

- Removed top and filled pump wth fuel
- Removed discharge hose to see if it would pump directly
- Disconnected line from tank to see if it would suck fuel from a cup
- Filled carb float bowl so that it could run for a minute to give the pump an opportunity to work


None of these worked and it simply won't pump fuel any longer. What am I missing?
 
There are two check valves, little diaphragms in mine, make sure they are in good condition and seating. Any defect will prevent fuel movement, the pump will just move up and down.
 
is it sucking air? A loose, dry or cracked hose. Anything like that on the suction side and nothing will happen.
You need to test the pump with a vacuum/ pressure guage.
a quick check with the pump off the motor is to work the pump with your finger in the suction hole. It should suck onto your finger, and you will feel the pressure on the delivery port.
Often they don't work because the lid on the pump, or the seal at the glass is leaking air.
 
I have had only bad experience of the new rubber gaskets lately.
The rubbercork ones seem to work a lot better.
Same if the checkvalves are the rubbertype they warp and leak.
Find the phenolic type.
 
ONE of the major failing points is the cover gasket. They can leak air and the pump will guit. Charlie most likely has new gaskets of Cork material. They still will swell with exposure to the fuel. After sitting I usually take a couple of wraps of electrical tape around the cover seam and get the car going then remove the tape. Robert Shewman sells a good flex fuel line from the fuel tank metal line to the fuel pump , see the V8 Times for his ad.
 
Treated cork seems to work best for these gaskets vs 'rubber' . Neoprene does not stand a chance against corn gas. It is possible the diaphragm appears OK but is on it's
way out. As mentioned the softer 'rubber' type valves can be trouble....not all but some.
My preference is the phenolic valves as well. Each valve sits on a dinky gasket and the slightest tear or imperfection can cause poor or no performance. Oops everything
has already been covered.
Charlie ny
 
Thanks for the replies. I'd just install an electric pump on it and be done, but it seems like they aren't lasting too long either, plus they have their own issues. The hoses are new, but I swapped them anyway to eliminate them as a potential problem. It did feel like it was sucking a bit, but not much. I haven't put a vacuum gauge on it but will. All the cranking put the hurt on my battery, and of course, my old battery charger died yesterday.
 
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I start engines that haven't been run for a while with starting fluid. Remove
the air cleaner and have someone spin the starter and as it is spinning give
it a few squirts of fluid with the thoatle plates open. As it fires give it short
shots of fluid to keep it running. Some will pick gas up and continue to run
in a few seconds and some may take a few minutes. If it don't fire in a few
seconds don't continue as there is an ignition problem. I have a large
collection of old Fords and have used this method 30 years. G.M.
 
If you have the flex fuel line on the input to the fuel pump, now is a good time to change it and avoid problems.
 
Terry said:
If you have the flex fuel line on the input to the fuel pump, now is a good time to change it and avoid problems.
Click to expand...

I use the Teflon lined flex hoses by Bob Shewman. These will not be
disturbed by and fuel or additives. He makes the standard type hose
and one with a check valve built into the hex fitting on the fuel pump
end. This helps hold fuel in the pump for easy starting. Both are good
looking high quality hoses. Contact gadgiteer@aol.com G.M.
 
Thanks G.M. I will order a couple from him.

While on the subject, is there a reference amount of travel for the fuel pump push rod?
 
Well, I posted the problem on Sunday night, received several helpful replies right away, and on Wednesday afternoon a fresh fuel pump from Charlie arrives at my door. Half hour later my '40 is purring like a kitten.

We sure got it good here.
 

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