Targa Miata
MIATA BUILD
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August 30, 2013 - I've been using a different bleeding technique for the brakes for a while: gravity bleeding.
It's about as simple as it gets, but I've found it to be really effective. It's something I learned from the old Land Rover, as it's got a particularly recalcitrant hydraulic system.
Basically, you just open up the bleeders. In my case, I just let them drool but you can attach a hose. You could open them all up at the same time, but I like to do one at a time so I can watch what's going on. Big bubbles are obvious, but there are a surprising number of little teeny tiny ones that you'd never be able to see if you were using a hose.
It's the same basic idea as pressure bleeding, but without the extra hardware. Some pressure bleeders can actually aerate the fluid slightly which is counterproductive. I've found that I get a much firmer pedal with this technique, which might be the result of that aeration or the fact that I'm getting rid of those miniature invisible bubbles. The brake pedal is like a rock. Plus the only thing I need is a wrench and a few rags to clean up. It's also fairly quick, especially since you don't have to mess around with the pressure bleeder.
It wouldn't be a quick way to flush the system, as you actually end up using very little fluid. But if you're changing out calipers (as I have been doing regularly recently), it's perfect. Just like with any other technique, I finish by starting the car and trying to push the brake pedal through the firewall. You develop a lot more pressure in the system that way, and it's a good way to find leaks that would evade detection during bleeding.
tags: brakes