Fuel Pump Failures

Hi Bill,

I have lost two fuel pumps on my Studebaker Car Hauler in less than two years and about 20,000 miles. One failure is as you described in that the hinge pin came almost out allowing side movement of the arm. I thought perhaps the rebuild quality was at fault?? I think the pump now on the truck is a new one and not rebuilt. Not enough miles on it yet for an endorsement.

Jack

I have a different fuel pump on my Transtar then you but I had to replace my Fuel Pump every year too. On me it seems to be the diaphragm blowing out and it doesn't matter what brand I use so far.

Rick(it must be the gas)Courtier

Is ethanol in the gas eating the diaphragm?

Mark

65 Cruiser

Who knows what is in Florida gas. . . at least Iowa tells you that they are adding corn.

I run the cheap stuff for the most part. . . however when the truck starts running rough I do add a bottle of STP and only on long trips to burn what ever is in the gas and it does smooth it out. This has only happen twice since I had the truck so I don't think the STP is the problem since I'm on 3 gas pumps and counting.

Rick

Exactly what's failing? Have you tried rebuilding an old stock pump, yourself? It's possible to tap the housing, at least on an "R" series pump, for a set screw where the aluminum plug normally holds the pivot pin in place - and leaks. There are two holes from the gasket surface to the pin; that could be used to get more oil to the pin, in the housing, if corresponding holes are drilled in the gasket and timing cover. The pin itself should be as longest you can find. Most cars can probably get away with lighter springs in the pump; both the anti float and the one that controls output pressure. New kits have diaphragms made of Buna-N, Nitrile rubber. That should hold up with alcohol or whatever. Mike M.

Can you put them in wrong? The one I am putting in now, just slipped in, shouldn't the arm go under the cam?

Its driving me nuts.

BG

I gave up on my mechanical pump on my 49 Commander, no matter what I did it would vapor lock if it was more than 80 degrees even when driving down the road. I made sure the air tube was connected and all shields were in place. I even wrapped the exhaust manifold. Nothing worked, I finally found an article written by one of the engineers about the 47-49 models and he said they only had one major field problem and that was "FUEL PUMP" vapor lock, which is why the air tube is there. I though about putting a thermocouple on the fuel pump and measuring the temperature of it I know it gets very hot to the touch. Since today's gas boils at 20-40 degrees lower temperature, what worked ok at 105 degrees ambient in 47 would cause the gas today to boil at 70-80 degrees ambient. The electronic 6-volt Carquest fuel pump has solved the problem, plus I have it wired to the oil pressure so it is safe. I chose to not even use the mechanical so I didn't have to worry about the diaphragm busting and flooding the engine with gas. It's one of those sacrifices one has to make to keep an old car reliable with today's gas, especially if one drives it 1500 miles a year. My aunt told me that even in the 40's and 50's fuel pumps weren't the best and vapor lock was common when it was in the upper 80 and

90's. She said the one in their 37 Ford blew diaphragms every year or two. She said they always kept a spare.

So that explains all your cousin's, huh? Jeff

"1949commander" wrote...

She said the one in their 37 Ford blew diaphragms every year or

Electric pumps on all my running cars except for the '56 Power Hawk which has an electric for initial carb prime only.

JT

1949commander wrote: