+1 on the valve replacement. At 2000 RPM, each one of those valves is opening and closing 17 times A SECOND! Are you sure you want to count on something produced in the 1950's or even 60's doing that reliably? Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Valid points from both of you. The reason for not replacing is I tried to remove the valves on a parts pump and could not get them out! The last thing I want to do is destroy this one. I will probably send it to Then and Now in the fall and I still have the NAPA unit that was working. That said, their new valves look very nice. I hope the NOS ones hold on for a few months.
Blue 50
1950 3100 w/57 235 Patrick’s Saginaw 4 speed and 3:55 rear end
New vs old style valves bring up the question of what is making all of the new pumps fail? The valves in the NOS and new foreign built units look similar and nothing like the new ones from Then and Now. Maybe that’s it?
Blue 50
1950 3100 w/57 235 Patrick’s Saginaw 4 speed and 3:55 rear end
I think it's a combination of factors. The bottom line though is extremely poor quality control. In the case of the failed fuel pump on my 1950 Chevy, it was poor poorly constructed. The lever arm was not assembled correctly.
The new replacement that wouldn't pump a drop right out of the box is anybody's guess. I suspect even a crappy valve would pump a little bit of gas, so that's why I suspect the lever arm was either not making contact with the cam or the throw is not calibrated correctly so it doesn't move enough to activate the diaphragm.
On other modern pumps, I've had the diaphragm tear after a short period of use. Most recently on some Cadillac pumps, the valves would not stay seated in the pump because of poor quality control. Maybe the orifice was machined a couple thousands over size and the valve wouldn't seat properly, who knows?
The only fuel pump I've had in the last 20 years where I can specifically pinpoint the exact reason for the failure, was the original fuel pump on my 56 cadillac. It died within 2 months of ethanol fuel being mandated in the city of Atlanta and metro area in general. The ethanol expanded the diaphragm material to such a degree that it would only pump half the specified volume of fuel required.
1950 Chevrolet 3100 (Ol' Roy)
1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)
