revised bleeder how to. forgot about the second bleeder screw on the booster. some have it and some don't.
Quote:
Originally Posted by dsraven
to bleed a hydravac you need to first bleed the firewall mounted master cyl at the line fittings. then bleed the bleeder screw on the top of the hydravac unit that looks like it is oposite of the supply line that comes from the master cyl on the firewall and if possible use a clear tubing so you can see if there are bubbles coming or not. be patient as this can take a lot of time to get the air bubbles from the firewall master all the way down to the frame mounted unit. you're gonna need a good supply of brake fluid and also keep checking the master cylinder fluid level. once you are absolutely sure there is no more bubbles from the first part then tighten that bleeder screw and go to the next bleeder screw on the unit which is close to the outlet where the line leaves the booster and heads off to the wheels. then when thats all good clean fluid with no bubbles go to the furthest away wheel and do that one next. a one man bleeder is handy for this as sometimes the "pedal man" and the "bleeder man" can get out of sync and that can allow air to enter. a pop bottle, partially filled, with the clear line set into the brake fluid and held there so it can't come above the fluid in the bottle is a decent way to bleed them so no air gets in. a tight fit on the bleeder screw to the tubing is also good and don't back the bleeder screw out a whole bunch thinking you will get more flow because that also leaks air into thee system when the brake pedal is released.some guys I know will try the reverse bleeding method where presure fed brake fluid is forced backwards through the system from the bleeder screws. i personally prefer the old fashioned pedal pump method. also ensure you have a helper to keep an eye on the master cylinder level so you don't suck air from that end. you gotta start over
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