The Stovebolt Site Forums The Shop Area Engine Shop Gas line attachment to fuel pump

I’m getting ready to install a new gas line on my ‘52 3100 with a ‘59 235. When I removed the old line, there was a 8” section of rubber hose connecting the line to the fuel pump. I looked in the Assembly Manual and it appears that the hard line is connected directly to the pump. This doesn’t seem to make any sense to me but I figured I would pose that question to the collective.

How is your fuel line connected to the fuel pump?

Hard line from carburetor all the way to a short reinforced hose with a female inverted flare on one end and a tapered pipe thread on the other which goes into the gas tank valve at the bottom of the tank.
The short rubber hose is there to compensate for movement of the cab.
A dealer installed glass fuel filter near the carburetor had a short section of rubber hose between the hard line (which had the flared fitting end cut off) and the inlet of the filter. The outlet of the filter was solidly attached to a 60 degree (?) elbow which was threaded into the carburetor.
As far as I know anyway,

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If the solid line from pump to tank is firmly attached to only the motor / transmission and has rubber for the final length to the tank, then yes. The steel tubing going to the pump can not be attached to the frame, cab, or fuel tank without a flexible section long enough to take up all vibration and movement of the drivetrain.

While my Truck is a Task Force and not an AD, this still may be of help. On the Task Force there is a fixed solid line for the tank that at transitions the a flexible rubber line to the frame and back to a fixed solid line to the fuel pump. At the fuel pump it uses a flexible rubber line

All of that said, I used a flexible rubber line from Jim Carter at both locations. I went with this hose solely because at had threaded fittings.

https://oldchevytrucks.com/me607.html

Phil, no one has answered your question directly so here it is; The factory setup uses a rubber hose with crimped fittings on each end to attach to the fuel tank petcock and the steel fuel line. This hose is available from the usual sources and uses threaded fittings, not nipples and clamps. (see pictures in my previous post)

The steel line runs along the frame rail and attaches directly to the fuel pump with no rubber hose. A steel line is used from the fuel pump directly to the carburetor with no other filters, rubber hoses, or anything else.

The only flexible line is the one between the petcock and steel line (which is attached to the frame rail).

Pre-formed steel lines match exactly the contours required and are the correct length to utilize the rubber hose which is sold by various restoration houses.

As long as a flexible line is used to transition from the tank to the parts that are all connected to the frame in some way, you'll be fine.

Unless you're trying to build a "numbers-correct" car show winner, common sense dictates that a flexible line is needed between the engine and the steel line down the frame rail, and another from the cab to the frame at the tank. However, common sense is a scarce commodity among stovebolters these days.
Jerry

The lines on my '51 are set up like Jerry indicates. The original style flex line out of the tank shut-off valve, steel line from there to just about the distributor point on the side of engine running along the frame rail, a 6" section of fuel grade rubber hose connected to remaining short section of steel tube and hardware attaching it to the inlet side of the pump.

Mine too. Makes more sense to allow the motor to wiggle a little when it wants to without possibly damaging any hard lines that might be connected directly to it.

My 3 have 3/8 ID braided rubber lines from the tank thru a filter to the Fuel Pump. Then 5/16ths hard line to the CARB.on my 235.

I have the flexible line from the gas tank to hard line to the fuel pump.

Thank you all for your contributions to this question. I know about the flex line from the tank petcock to the hard line attached to the frame, but I would have thought GM engineers would have also installed one at the fuel pump.

My truck is not a numbers correct build so in addition to the flex line at the tank, I’m going to install one at the fuel pump.

Thanks everybody for your input!

Before y'all go consider my rig. A 1951 3800 pickup. When I got if from the second owner 54 years ago, it had a hard line running along the frame and clipped to it from the flexible tank hose to the fuel pump. The hard line was clipped to the frame at about 2 feet from the pump. That gave plenty of distance for the hard line to flex as the engine rocks from torque. The line connected to the pump about 15 degrees from parallel to the block. I have a couple of pumps with the inlet connection at this angle. Later pumps connected parallel to the block. Still later pumps connected perpendicular to the block. Depending on which pump you are using you can either connect the hard line direct to the pump or you'll need a flexible hose. Given the prevalence ethanol gas and its effect on various plastics and flexible hoses, I would attempt to stick with the hard line if possible.

Yes. I don't think there's any need for a an additional hose between the hard line and the pump. There's a lot of wiggle room there.

I had a problem with an aftermarket short hose with the fittings on it. The rubber turned to runny tar and leaked like a sieve within months. I replaced it with with modern fuel hose and moved on.