240D - replace rusty fuel lines with hose?

[efm-7]

I have the rear subframe dropped right now for some rusthunting and found some flaky fuel lines.

I am wondering what my replacement options are. I've been toying with the idea of replacing the whole lot (supply/return) lines with rubber hose.

The thought of bending new steel lines seems daunting to me because I'm a weakling. And judging by how awkward it was to take out the old lines, they might have to be done in two pieces to clear the power steering box.

I've also considered Nickel/Copper lines since they're supposedly more pliable than steel - however, very expensive at over $50 per 25' run which I imagine I need 2 of.

What are the arguments against rubber hose? Any other flexible options out there?

[oldsinner111]

they run rubber hoses in some wvo conversions

[efm-7]

It just seems like one of those "too easy to be good" solutions.

I read a thread on some cummins truck forum that discouraged the idea but nobody gave a real reason as to why not.

[jay_bob]

I suspect it has to do with the fact that rubber hose could be cut by road debris.

[efm-7]

Originally Posted by jay_bob

I suspect it has to do with the fact that rubber hose could be cut by road debris.

Perhaps - but aren't the flex hoses on the brakes just as suceptible? they seem to hold up just fine. Granted, they are in a different location and different type of hose. I can't see that being too much of an issue as long as there isn't huge dangling slack.

[Simpler=Better]

The steel lines lasted since the early 80s. Rubber lines tend to break down after 10-15 years.

Personally, I would run cheap carburetor-grade rubber fuel lines all the way front to back. No need to waste money on fuel-injection rated hose (the 61X motors don't pressurize the lines).

Make sure the tank strainer is clear, if it's blocked I could see the IP collapsing the rubber lines when it's trying to suck in more fuel (not a catastrophic failure, it would just make it drive slower until the screen was cleared).

[Simpler=Better]

The steel lines lasted since the early 80s. Rubber lines tend to break down after 10-15 years.

Personally, I would run cheap carburetor-grade rubber fuel lines all the way front to back. No need to waste money on fuel-injection rated hose (the 61X motors don't pressurize the lines).

Make sure the tank strainer is clear, if it's blocked I could see the IP collapsing the rubber lines when it's trying to suck in more fuel (not a catastrophic failure, it would just make it drive slower until the screen was cleared).

[t walgamuth]

If there is an actual leak I would cut out the bad pipe and replace with rubber hose. No way I'd remove all of it. There will be spots that collect debris and rust out. 95% of the steel line is probably good for another thirty years.

[funola]

pm me for some clear nylon hardlines. tough, easy to run. lasts a long tine.

[Graham]

I have had a number of fuel line leaks over the years. Some at rear where line jogs around a bit and then under the rubber in the clamps.

Took it to local garage seeing they have a hoist They said they would use the new and modern nylon (or whatever the plastic is). They even showed me the special kit and tools they had for making the joints.

When they came to actually do the job, they decided to use steel lines. They kept the old front steel section which was in good shape. It has several bends. They connected to it with metal union connections at front. At rear, they used rubber hose double clamped. They replaced the complex shape at rear with mostly rubber hose, I think.

I noticed the lines now have surface rust, so I wiped them down and coated with Penetrol.

By the way, on my 72 R107, there are many rubber hose connections in the fuel system and it runs at 2bar pressure. But main runs are steel.

[efm-7]

Wow, I love this forum. Many replies in such a short period glad I picked up this "project"

Some areas are obviously worse than others. I figure if I'm going to have the subframe down, might a well do the brake and fuel lines.

The vent line, while a bit rusty, I'm just going to treat.

All the lines above the subframe look like this:


I'll be reusing a small portion of the original fuel line within the engine bay so I have something to clamp into.

I think I'll be using rubber or as someone here suggested, nylon.

[JB3]

Ive used rubber on a bunch of cars. Personally I prefer it, easy to repair if it gets damaged or cut, cannot really be crushed or rust like steel lines, and easy to run.

Id do it, lots cheaper, lots easier, negligible downside. As already said, there are rubber ends to the tank and engine at both ends that last pretty well, no reason you can't get many years out of easy to do rubber.

[moon161]

Just did it Friday night, as the spotting quickly got worse. I quickly remembered how much of a PIA steel hose his if there's any, you know, car in the way, more so when slick w/ diesel that is also dripping in your face. It also occurred to me that I had a family that might miss me while I bend and cuss. Ran 5/16" fuel line from engine compartment, cut at a clean spot and put 2 clamps on it. Did both lines, they pass through the same bushing that probably traps water at the same spot. Ran my lines straight to the solenoid valves (greased car) use one hose to cap the hard lines, put the other in my tool box. Zip tied to existing lines and my TIH line. Good till the other end or the brake lines go. Additional nuisance: the rubber bushings that hold the lines together doesn't split, must be cut or replaced.

If it doesn't want to prime easy, you can blow on your return line, or have a helper pressurize your fuel tank w/ a shop vac while you prime.

[Diesel911]

I cut out the leaking section on My Fuel Tubing that had rusted thru under one of the Clamps and replaced it with Hose.
But, I did not replace the complete Fuel Line
However, one of Our Members replaced the whole Fuel Line with Hose and attached the Hose to the Old Tubing with Electrical Ties.

The Also sell Aluminum Tubing. OSCh Hardware has it and likely others also. It is easier to bend than Steel Tubing.

[cooljjay]

Technically if you were worried about the rubber lines getting damaged under the car, could one just run the lines through the interior of the car? Under the black plastic ducts that old the vacuum lines/wires...