Brake Lines

[pflaming]

Central CA, where I live, is hot and dry. I am thinking the brake lines may be OK. Is there a way to test them? I will need new wheel cylinders, once they are in is it possible pressure test the lines? Is it possible to pressure test the lines before they are connected to the cylinders? I'm not crazy about pulling the lines out, at least not without a lift.

I was thinking of forcing some BP Blaster in each line, then slowly blowing it out to clean it, them follow up with some brake fluid, blow it out to clean out any remaining BP Blaster. Is this sensible?

Thinking: rig up a gauge to attach to the pipe end(s). Then a valve on the other end, put tranny oil (red color) in the line under pressure and watch for wetness / color?????? It if worked be cheaper and easier than all new lines.

[carl b51]

Paul, NO PB Blaster use the fluid you are going to use in the lines You don't want to contaminate the lines. If you want you could use brake cleaner. Use air pressure in the lines to look for leaks. Carl

[grey beard]

Paul,

Those brake lines typically rust through from the INSIDE because of the hygroscopic nature of brake fluid. They may look okay on the outside, but I would strongly suggest you replace them.

I bought a 25-foot roll of steel tubing and had some left over when I was finished. Just pull each old line off carefully. If you don't have them, buy a set of three fitting wrenches - they look like a box end with a hole in the rim - and use these to break the old fittings loose. There are two short lines on your rear axle, a long line from the master cylinder back to the flex line abovce the rear axle, and two medium length lines going to the two front wheels. A special junction fitting is on the frame near the master cylinder, and one short line from the master cylinder to the junction block is the only one that is one size larger - 3/8-inch, I believe.

You can do the whole job in one day, if you first learn how to make proper double flares on the line ends. If you are unsure of this, ask someone locally who inws how to show you - it's quire easy once you've seen it done. The only other tool you will need is a double flare kit -Haebor Freight sells 'em.

Use youre old lines as patterns for lengtrh and bends. Put two big deep sockets in your vise and use them as a bendng mandrel to form your tubing bends, so it will not kink.

I'd also recommend you replace all three rubber flex lines. Then your brakes will be safe and dependable. You'll be glad you did.

Good Luck

[Dave72dt]

Pressure testers are available. Air pressure isn't high enough for brake lines. How much pressure can you develop when standing on the brakes during a panic stop? When you need them the most is the most likely time for them to fail. Replacement is the best policy.

[oldmopar]

As the others said replace the lines I have done many with vehicles on jack stands. I also use preformed lines and a few extra couplings . Dealing with single cylinder master cylinders best option is to change every brake component.

Its really a matter of safety no brakes you crash and that is a lot more expensive and time consuming.

[pflaming]

Dave Erb had me convinced, the rest of you confirmed his message. I hate concrete floor and autostands, but with good planning and a couple extra alieve and I should survive. Better this than the tail gate of a semi from Texas in my windshield!!

Follow up: In hind sight I should have changed the lines when the dog house was off, would have been much easier working from the top than from the bottom. Fortunately the bed is not attached, so will remove that to make the rear a lot more accessable. Point is this, there is so much that can be done much easier if the front fenders and bed are off. To one who is starting that is my suggestion.

Edited June 20, 2010 by pflaming