Brake flushing

[dostrander]

Hi Guys, I have a 2001 Pathy and I'm wanting to flush its brake lines. I was planning on just opening the bleeders on all 4 and letting it gravity drain overnight. A question I have is I've always heard not to let your reservoir go dry, I know mainly so you don't start pumping air into the lines while driving, but is there another reason like once the master cylinder is empty its hard or impossible to re-prime it?

[smj999smj]

If you let the master cylinder bleed to the point where the reservoir goes completely empty, you can introduce air into the bore cylinder. If this happens, you will need to bleed the master cylinder before bleeding the rest of the entire brake system, which adds a lot more work. Personally, I wouldn't recommend your idea. You should either pressure bleed them or vacuum bleed them. First, use a turkey baster or similar tool to suck most of the brake fluid out of the reservoir and then refill with clean fluid. Bleed the system as follows: right rear, left front, left rear, right front...occasionally stopping to check the fluid level in the reservoir and top off as necessary. If you have a second person to help, I would just pressure bleed it. If you don't, I've used a vacuum bleeder kit for years and it works great. Here's a similar kit to mine for $25 that should work:

http://www.ebay.com/itm/2-In-1-Brake-Bl ... 1265672658

[dostrander]

Ok, so the master cylinder wont self prime and would need to be bled, that's what I was wondering. Guess I'll be using the ole dangling hose in the jar method. Thanks for all the info!

[smj999smj]

They also make the one-man brake bleeder hoses; Lisle Tools sells them, but I've never used them personally. It's a single hose with a one-way valve. You install it on a brake bleeder and crack it open and it allows you to pump the brake pedal without sucking air back into the system. Then you just go back and tighten the bleeder and remove the hose.