Beringer brake no pressure - burbling in master cylinders while bleeding

I've had Beringer brakes for the life of my bird, and have never had issues bleeding them each year during my condition inspection / winter maintenance tasks. This year, the left brake (surprise, surprise, from what I've read in other threads) just will not bleed.

Normally I bleed with the master cylinders completely unbolted and laying horizontal in the groove between the rudder pedal tubes. I never even thought of leaving the top bolted and just the bottom up until horizontal (thanks bkervaski, in another thread in the archive!). Anyway... This year, the left brake, when I pump the cylinders a few times as they bleed, I can hear bubbles burbling in the cylinders. And there is a large air gap in the bleed line before the fluid starts running again. Even if I didn't pump the cylinders, there are decent air bubbles flowing through, more than I would normally see.

I've checked the caliper, checked the masters, replaced the copper gaskets, about the only thing left is the regulator. What/where else should I try? I have to imagine the air is being sucked in somewhere under vacuum during bleeding, because otherwise wouldn't I see a leak somewhere?

At a bit of a loss this time around. Especially when I can hear air burbling in both master cylinders when they're pumped.

I am wondering why you need to bleed them each year. This is my first year using Breinger but with Grove and other brakes, I never had to bleed them unless I worked on it and introduced air to the system.
As Bringer goes, I learned also the hard way to unbolt and have them nearly up side down for bleeding.

Most years it's just a habitual task on the checklist. Some years as part of other tasks I have the wheel off, caliper unhooked, etc to do something else. Next year I'll be replacing the brake pads. Recharging and bleeding just tends to be something I do every year for whatever reason.

I think tomorrow night I'm going to turn down the regulator all the way (saw that in another thread), maybe unscrew some banjos to check that the braided line is okay at the joints, etc, and have the masters horizontal but still bolted at the top. Having the masters sitting in the rudder pedal tube groove does tend to twist the braided lines more than they already are.

Are you sure your pressure pot is not introducing the air?
(assuming you are bleeding from the calipers up).
Also bleeding is only required after rebuilding cylinders unless somehow air got into the system.

My first question was also "why are you bleeding the brakes at annual".

Waddington effect comes up as my second thought.

Honestly never heard of the Waddington Effect until tonight. Thanks for a funny-because-it's-true chuckle Mike.

sbalmos said:

Thanks for a funny-because-it's-true chuckle Mike.

Click to expand...

Glad to help.