Leaking Fuel Pump Diaphragm?
 

My fuel tank is still located in the cab behind the seat and I know that if I disconnect the inlet line from the mechanical block mounted fuel pump the fuel will drain the tank dry without hesitation.
My question is that if the mechanical fuel pump diaphragm were to rupture or crack sometime due to age or something would it be possible for raw fuel to find its way into the crankcase?

Re: Leaking Fuel Pump Diaphragm?
 

Yup. Fuel can flow until the level in the engine is the same as the level in the tank.

Re: Leaking Fuel Pump Diaphragm?
 

That is scary! :eek:

I might drive my truck every few days now that I'm retired and it's embarrassing to have to crank the engine over for 20-30 seconds every time before it finally starts using today's fuel. :mad:

So I've decided to eliminate that problem by deleting the mechanical pump and replacing it with an electric.
Yea this pump is probably overkill but those selinoid pumps sound like a friggin' jackhammer. :rolleyes:

Thank you for the reply and Happy New Year! :three:

Re: Leaking Fuel Pump Diaphragm?
 

You're welcome! I have an electric fuel pump that my FiL put on. He did it because he would run a saddle tank dry and the switch tanks. The electric pump got fuel to the engine sooner. It is a solenoid type, and yes, it's a real clacker. I do use it if the truck hasn't been started for a few days.

Re: Leaking Fuel Pump Diaphragm?
 

Going to electric I would put an oil sender safety cutout on it or an inertia switch .

Re: Leaking Fuel Pump Diaphragm?
 

I totally agree with you on that suggestion (thank you :))although an oil pressure switch would probably put me back in the same hard start boat I'm already in.

If I get hit hard enough to rupture a fuel line or even the in-cab tank itself, the fuel isn't going to need any help spilling everywhere.

There's something to say about peace of mind though.

Standard Motor Products FV-7 Fuel Pump Cut-Off Switch Assorted, One Size https://a.co/d/7eUrqhi

Re: Leaking Fuel Pump Diaphragm?
 

Had to bend the fuel pump bracket so that I could wrap it over the frame but I think it will be fine.
Trying to fabricate everything together before I do the actual swap so that I can still drive the truck in the meantime.
More parts arriving tomorrow like pre-pump filter, electrical etc.
The pump is probably within a foot of the gas tank as recommended but truthfully the tank will feed fuel all the way to the mechanical pump up front anyway so there shouldn't be any problem.
Will probably put in a little tin shield between the exhaust and the pump just to keep it cooler.
ETA: You might be wondering why I didn't just stick the pump inside the frame.
I think it would be too tall and there is 56 year old metal brake line tubing in there I didn't want to risk damaging...it'll work. :D

Re: Leaking Fuel Pump Diaphragm?
 

I think the pump bracket installation will prove to be the most difficult part of this whole project.
I'm 67 years old and I fell on Christmas eve and injured my ribs so two weeks later it still hurts to crawl around under the truck.
Turns out walking while intoxicated is almost as stupid as driving while intoxicated.
Anyway there was already a hole in the upper frame and also some extra clearance in the cab for the seat perch which makes it easier to install and remove the pump in the future.
Oh, and I got the inertia switch yesterday.
I'm in no real hurry to finish this job as the truck is still drivable with the mechanical pump working.

Re: Leaking Fuel Pump Diaphragm?
 

Hope your hearing is bad and you won’t hear that constant loud buzz from the pump.
You can reduce it by using some 1/2 inch thick rubber between the bracket and the frame.

Re: Leaking Fuel Pump Diaphragm?
 

I'll never hear it. :cool:

Re: Leaking Fuel Pump Diaphragm?
 

:lol: BOOM BOOM BOOM whirrr

Re: Leaking Fuel Pump Diaphragm?
 

You’ll still hear it!
And the kicker is it won’t change your starting problem.

Re: Leaking Fuel Pump Diaphragm?
 

You have no idea how loud I crank my stereo and it will refill my float bowls before I turn the key so yes it will fix the fuel evaporation issue and start the engine right up.
And I'll stop worrying about a crankcase full of gasoline when the mechanical fuel pump diaphragm finally fails.
You sound like a geezer. :rolleyes:

Re: Leaking Fuel Pump Diaphragm?
 

So what’s the pressure output on that pump?

Re: Leaking Fuel Pump Diaphragm?
 

Good question, I think it's low enough to not require a regulator but...
Carter Electric Fuel Pump https://a.co/d/3nUCTlr
It's supposed to be quiet but if not I'll just tell everybody it's feeding duel 4 barrels and leave the hood down. :lol:

Re: Leaking Fuel Pump Diaphragm?
 

IT SHALL BE GLORIOUS! :metal:

Re: Leaking Fuel Pump Diaphragm?
 

...ok so what the heck is this supposed to shrink around? :haha:

Re: Leaking Fuel Pump Diaphragm?
 

Time to figure out how I'm going to route the electrical wiring for this pump, and we all how good I am with that stuff. :lol:

Re: Leaking Fuel Pump Diaphragm?
 

OK I now have everything I need to complete the job, except a garage heater.
I'll find this thread and keep you updated...next spring. :rolleyes:

Re: Leaking Fuel Pump Diaphragm?
 

I've used one of these for years.

https://www.revolutionelectronics.co...Fuel_Pump.html

Re: Leaking Fuel Pump Diaphragm?
 

Thanks for the idea. :)

Years ago I switched to electronic Ignition and ran 12V directly from the battery to a separate on/off switch, it has worked well for years and now I'm thinking just route the Ignition plus the pump through a relay so I can throw the switch, wait a few seconds for the pump to fill the carburetor bowl and then turn the key.

Re: Leaking Fuel Pump Diaphragm?
 

I just wanted you people to know how impressed I am with myself for my fuel pump wire routing from under the dash to inside the frame.
Yea that's about as far as I got so far but that took some serious planning and sweating on my part and the garage is freezing.
I put a piece of vacuum line through a preexisting hole in the frame and secured it with tiny zip ties both top and bottom and fed the pump wire through that to prevent any chafing and the wire is a safe distance from any headder heat.
Believe me when I tell you I'm getting older and I'm out of shape so it takes more effort to accomplish this stuff.
And It's getting harder to reach around and pat myself on the back but I'll definitely manage that. :cool:

Re: Leaking Fuel Pump Diaphragm?
 

Can someone explain the electric fuel pumps to me like I am a 3rd grader. Are they connected to a relay and the ignition so that is how they come on and what keeps it from just flooding the carb if you turn just the ignition or a pumps switch on.

Re: Leaking Fuel Pump Diaphragm?
 

Good Job!

This might help.....
.

Re: Leaking Fuel Pump Diaphragm?
 

:lol: Indeed, good job!