Introduced Air While Flushing Brakes

[boba7523]

Hi guys,

I was doing my year 2 maintenance and flushed my entire brake system using the Motive pressure power bleeder but have introduced air to the last caliper because I ran out of brake fluid in the bank.

While I was releasing old fluid, I started seeing air bubbles come out and suction sound indicating there's no more fluid left in the bleeder tank.

I immediately tightened the bleeder screw and checked the brake cylinder and saw that it was empty (below minimum). Prior to starting, I made sure to fill it to "Max."

My question is, what should I do to correct this?

• Do I just fill the brake cylinder back to full and fill the bleeder tank, and finish off the flush, or would I have to start everything over again?
• Or did I cause an even more serious problem?
• I've heard to never let the brake cylinder run empty to avoid introducing air but I'm afraid that's what happened thus causing the air to come out while bleeding.
• FWIW, I never pressed the brake pedal the whole time I was doing the flush, not sure if it matters...
• Also, I'm concerned about air in the ABS system now and I'm not sure how to resolve that with ISTA+

Thanks for your help

[MineralWhiteF80]

it's impossible for anyone on the forums to know exactly how much air intrusion actually may have occurred. But, if you were bleeding the last caliper and fluid was coming out the bleeder normally and all of a sudden a lot of air started coming out, it's likely you ran the brake fluid reservoir dry and your brake pedal pressure probably feels horrible.

With that said, it's best to simply re-bleed all four calipers using the standard brake bleed procedure and then test pedal pressure. Once you have the car in the air and the wheels off, actually bleeding the calipers goes really fast. If you have ISTA on your computer and an ENET cable, running the DSC (ABS) bleed procedure can't hurt. The procedure is easy to follow with the step-by-step instructions through ISTA. Hardest part for me is always finding the correct section within ISTA that has the DSC bleed procedure lol