Brake line maint

[bills2002]

My project car brake lines have been dry for 20 years. I want to run some fluid through them to ensure no dust etc. makes it into the calipers. Is there anything other than brake fluid I could use that is a little more environmentally friendly while not compromising the brake system? Mineral oil? Im just thinking that this process uses an extra quart of BF and im not sure that can be recycled with used oil. I will follow that procedure with a bleed of new brake fluid, then hook the lines up to the calipers and cylinders.

[mike472]

Forget about just running brake fluid through. Your brakes are important. You should start by replacing the probably swollen 35 year old rubber brake lines. I would do the rigid metal ones too. They're cheap enough at your local NAPA store. Use the metal braided lines in place of the stock rubber versions from one of the FAQ vendors. At the very least do the rubber replacement then do your flush with DOT 4 brake fluid. Use either a pressure bleeder or a MityVac vacuum type bleeder. Avoid the pumping of the pedal type bleeding. Bleed until you see clean fluid come out of the right rear bleeder.(start bleeding there) As far as being environmentally friendly, just bring the old fluid to anyone who takes used motor oil. Don't use mineral oil. I don't think it's compatible with brake fluid and you may not get all of it out. It might damage seals if you don't.

[///mChris]

You may want to think about saving time and money and replace them. OEM lines aren't too expensive. I wonder how the small amounts of brake fluid in a dry line did with the inside of the brake line. I know mine are pretty corroded. I plan on replacing them.

The brake lines take several hundred PSI. I've never heard of one bursting, but I'd hate to be the first.

[photog02]

Whether you get braided or not, replace them. Twenty years is an awfully long time for rubber, under any conditions, to sit.

[Guest Anonymous]

Thanks Mike. I'll be replacing all rubber hoses and calipers/cylinders (wheel and master) but the rigid metal lines are all good. I'll use DOT4 BF if I can take it to the oil recycle center. The only concern I have is that dust or very tiny insects may have gotten inside the lines, thus the copius bleed before attaching said lines and appliances to them.

[bills2002]

Here's what an experienced rebuilder/racer just told me: Use alcohol to purge the lines. You can let it drain onto the floor and it'll just evaporate. No worries with paint damage either. Once the lines are purged with alcohol blast them with compressed air. Now your lines are clear and dry, hook 'em up and fill the system with brake fluid.

[JohnS]

Yes, use denatured alcohol (available at most hardware stores). It works great for cleaning up brake fluid too.

At least here in Santa Cruz California, they do accept brake fluid along with used oil at the recycling center at our county dump. I too thought it was odd that the guy at the recycling center told me to "just pour the brake fluid into the same tank with the used motor oil".