Questions and Answers

Rotten Toyota Corolla Fuel Lines Q. Hello Mr. Ciulla: I have a question regarding replacing the high pressure main fuel line, return line and vapor lines, all original, on my vehicle. 1990 Toyota Corolla 1.6 litre 4A-FE Manual transmission Mileage 365,000 km (not a misprint!) Fuel Injected P/S, A/C Rack and pinion steering

The three lines above and the rear brake lines all run beside each other. The brake lines are new and in good shape. I have purchased the three steel fuel lines (high pressure main, return and vapor) from a Toyota dealership. I also have new clamps (for the return and vapor lines) and banjo washers for the new fuel filter I intend to put on.

My biggest concern is the rear side of the high pressure main fuel line. It has a threaded fitting (but no "O" washer according to Toyota). It is threaded into a very corroded looking (but not leaking) fuel output line that feeds into the top of the gas tank and into the fuel pump. There are no leaks in the fuel system at this point but I am trying to be proactive as these fuel lines are now 16 years old having seen 16 winters!

What is the best way to carefully loosen this fitting without damaging the line that is leading up into the top of the fuel tank and into the fuel pump??? I do not want to break this line as I will have to drop the gas tank to replace it. I have soaked the outside of the fitting with WD40 but is there anything else I can do to help prepare it for removal?? I obviously cannot heat it like I might do for a seized manifold thread or a seized brake caliper bolt! Any ideas?

Thanks for your help...
Mike

A. Gee... a Toyota with rotted fuel lines... how unusual... not!

Anyway, I would be nervous about it as well. I try to avoid threaded connections whenever I can since they are prone to breaking. Some things you can do to improve the odds are to soak it with penetrating fluid, as you have done. Tapping the fitting with a hammer to help break the rust bond as you apply pressure with a couple of line wrenchs.

Work the fitting back and forth and don't try to remove it all in one shot. Once it breaks loose, turn it off a bit then spray it. Then tighten it a bit and just keep working it back and forth, taking it a bit looser each time until it comes off.

What I do to avoid moving and old fitting is to locate a good section of fuel line about four or five inches long and cut it with at least two inches of good line on either side of the cut. Then I use a compression fitting to splice in the new line. I compression is good to use on a fuel line but not really recommended for use on brake lines.

If that is not an option, then try the methods I just outlined and good luck with it!