Old Toyota 1.6L engine, fuel injected. Main line (steel tubing) fuel tank to engine, developed a pinhole leak. I cut off bad part but surface of remaining fuel line is still rusted. I cleaned up best I could, but I may not get a good double flare. If double flare does not work I am thinking of replacing worst part of line with high pressure hose. I think max pressure for this line should be no more than 40psi. I am thinking of coating end of steel tubing with epoxy, then sliding hose over tubing, allowing epoxy to set, then clamping with a few ss clamps. Has anyone ever repaired a line this way? Replacing complete original line is not doable without removing intake manifold-too much work for an old car.
I ran new fuel line from just out of the fuel pump cartridge at the top of the tank to the engine with a copper clad steel automotive steel brake line a few years ago. This was in 3/8", and 3/16" as the originals were rusted and leaking. This bends/forms easily, and does not give problems. I used steel compression fittings as are required in hydraulic systems rather than household plumbing brass.
What did the steel compression fittings attach to? I have to attach to the old line, as I can't reach the end that attaches to the engine.
The lines leaving the fuel pump cartridge were plastic swayed onto steel which ran along the frame rail. Same thing on their other ends that swaged back to plastic running to engine. I cut the steel ines leaving about an inch stub and connected the compression fittings to these stubs.
I have spliced steel fuel lines with hoses that are used in fuel injection systems. I put a slight flare on the steel liens to prevent any chance of slippage. I bought it at Auto Zone, but any auto parts store will have it.
Thanks. I didn't know compression fittings could be used on pressure lines, but I used them when plumbing my house and that takes 65psi, so I guess it should work.
What did you use to clamp the hose to the steel line? Also, it seems that a flare might make it difficult to install the hose; I'm thinking of using a double flare die to barely start the first part of a double flare, which should form a slight bubble with round edge.
Hydraulic compression fittings use a hard steel ferrule that ensures a tight seal under pressure. Brass ferrules used in household plumbing are for use with much softer tubing, or pipe which is usually copper.
I just remembered that the steel line is pitted, so I fear that a compression fitting would leak.
I did not cut the plastic. I cut the steel line only on each end.
You need clean, pit free tubing to ensure a compression fitting won't leak. It was no problem to slide the hose over the flares. I didn't make a complete flare. Just a lip. I used two stainless steel hose clamps on each side of the splice.
Thanks.
I assume the hose under compression would fill in any small pits or gouges in the original line? I was going to coat the steel line with a thin layer of epoxy before sliding the hose on.
I did it dry. I wouldn't epoxy the steel line. It prolly wouldn't bond to it permanently. Yes the hose will pinch down and seal quite well. I repaired some very nasty fuel lines in my day.
Yeah, I didn't intend for the epoxy to bond, just act as a filler that wouldn't be degraded by gasoline. By the way, I just want to be sure I'm understanding that you repaired pressurized fuel lines for fuel injected engines? I've done a lot of low pressure lines on carbureted engines. I don't know exactly what kind of pressure this fuel pump puts out, I'm guessing 30-40psi.
How long do you think it will be until that remaining old piece develops a pin hole as well? Replace the whole line. Disassemble whatever is needed to access the entire thing.
I repaired my son-in law's Chevy Silverado pick-up truck, it was the supply line for the throttle body fuel injection. About 40 to 50 PSI. It is amazing how long a pitted steel fuel line will last. I replaced the engine cradle in my grandson's Chevy Malibu. The fuel lines were pitted really bad and I told him they need immediate replacement. He didn't. He sold the car over two years later and they still weren't leaking. I know they weren't because I asked him when he sold it.
Inspiring! I'm gonna do it. Thanks for all the info.
Not worth it; 31 year old car, 213,000 miles. Just used for "emergencies", as I have two other road vehicles. The part I am replacing was the worst, in the most vulnerable position in the line. If you ever get the opportunity to pop the hood on a 1992 Corolla alltrax wagon try and visually trace the incoming fuel line. But, generally speaking, you are right.
At the auto parts store you should be able to get "fuel injection" hose, as opposed to general purpose fuel line. Just run the whole line from the tank. Rather than making a mess with epoxy, use a brake line flaring tool to put a bit of a bubble in the steel line before you slide the rubber line over, then use two hose clamps. Just make sure the rubber line is sized to be snug on the steel.
To hold the hose splice in place use a jumper from one end of the steel line to the other. I have used stainless wire and have hose clamped it to the parent line past each end of the hose splice. This way the hose isn't being pushed off the steel line.
The epoxy is to fill in the many imperfections on the surface of the steel tube. I'm going to make a slight bubble with the first step of a double flare, and yes, high pressure hose.
Seems like a good idea.
Closing the case: I removed worst part of steel fuel line from tank forward, about 4 feet. At that point original line appeared to be in good shape. I made up new steel line from tank to remaining line (using 2 pieces including 4 double flares) and double flared the existing line to hook up to the new one. Flare on old line leaked due to rough interior weld preventing leak-free connection to inverted union, so I cut off final flares, made a slight bubble with double flare die, and used high pressure hose and clamps for final hook up (as per Tinkerer). Thanks all for interest.