Leaking Fuel Pump Diaphragm?

[BRL]

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?

[Steeveedee]

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

[BRL]

Originally Posted by Steeveedee

Yup...

That is scary!

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.

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.

Thank you for the reply and Happy New Year!

[Steeveedee]

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.

[72c20customcamper]

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

[BRL]

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

[BRL]

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.

[BRL]

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.

[geezer#99]

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.