I got out of my truck yesterday and saw some diesel dripping down my rail on my truck. I turned the truck on and watched it drip out of the return line under the driver door. Its not leaking bad at all but there is a hole. Is that a high pressure line? Can I just fix it with rubber hose? Would it be alright to drive it like that to a autoparts store?

 

Your line is steel isnt it? Aside from the injector line, all fuel lines on these old trucks are low pressure. Usualy 8psi max after the lift pump and almost no pressure on the return line.

Youd be fine driving it to the auto parts like that as long as its a slow leak. If it was on the supply side I would say no because it will suck air.

Just a simple 3/8" fuel line and a couple clamps and your back in business.

 

thanks for the quick response, I think the high pressure line is the line on the rail with the two fittings so if it rusts you can exchange that little part.

 

the lines to and from your fuel tank are not pressureized at all. The fuel is pulled by vacume by the lift pump from the tank, and return fuel is mostly gravety return. You only have fuel under pressure between the lift pump and injection pump, and then thats only 8psi max. Normaly about 5psi. You can replace all of your fuel system lines with plain old 3/8" line if you wanted.

 

The return is 1/4".

 

EXCEPT the six high-pressure injector-lines from injection-pump to injectors.


The reason vehicle manufacturers use steel fuel-lines along the frame rails is as a measure of expediency in the assembly-line.

When you are using them by the box-car load, pre-formed rigid steel lines cost little if any more than mediocre-quality rubber lines, and are much quicker/easier to fasten along a frame-rail.

Over the long haul, good high-quality rubber lines are actually superior to the steel, even better than stainless.


Rubber doesn't rust, vibration has little effect on it, and is much safer around welders, besides being so much more user-friendly.