Replacing rusted front brake line 86 K20

[VTKidder]

The line running from the drivers to passengers front wheel rusted out on me, and I'm going to be replacing it. Is the line 3/16" or 1/4"? Are there any pitfalls to look out for? I'm pretty skeptical that the line will separate from the junction block on the drivers side. Could end up doing the entire front end before I'm done. Any words of wisdom?

[Eyegore]

If in doubt buy both and take the one you don't need back for a refund. I had the same problem on a 80 K5, the junction block was not the problem the connection at the caliper is where I had trouble, try soking it with penetrating oil first or at least coke cola. also check your bleeder fitting it could be rusted shut like mine was.

[Jason Spears]

The line from the combination valve to the flex lines on the front is 3/16".

The first thing you do when starting a brake job is to try to get your bleeders open. Nothing is worse than replacing a brake line and the finding your bleeders seized when you go to bleed the line. If you can get the bleeders open without breaking them off, your job is much easier.

The best advice I can give you for trying to get rusty old lines out is to cut the line as close to the flare nut as you can and use a socket to try to get it out. Its pretty easy to round off the rusty old flare nuts, even with line wrenches. Of course you should use a penetrating oil or heat if you have it. If you use heat, make sure the line is open ended so it won't blow up.

A double flare tool kit and a tubing cutter are required if you need a custom length of line. This is and investment that will pay for itself in no time if you replace a lot of brake lines. A tubing bender is also good to have but not required. It just makes the finished product a lot neater.

Jay.