Bench Bleeding: how many strokes?

[Safety Guy]

I'm bench bleeding my M/C right now and I've done maybe 10 to 12 strokes of about one inch length to it (depth per the installation instructions: "3/4 to 1 inch").

There are still air bubbles coming up, but not all the way to the clear tube outlets submerged in the reservoir. Do I just keep stroking or should I shorten the tubing so the air bubbles don't have to travel as far to purge themselves?

Karl

[FB71]

keep doing it till bubbles stop

[Safety Guy]

Okay! They're getting fewer now.

Karl

[FestYboy]

i like gravity bleeding myself, keeps the fluid from being agitated (small bubbles). you don't want to pump somuch as push the fluid through (single pump of the pedal then close bleeder while pedal is down, lift pedal and apply pressure again, open bleeder, repeat)

[Safety Guy]

Festyboy, that's what we did to bleed the system. I was talking about "bench bleeding" the master cylinder before installation into the car. You prep it by filling it with fluid and pushing the piston by hand to get the air out of it.

At any rate, I installed the M/C and we bled the brakes. Everything was a go until I tried starting the car on the stands. Dead battery! Then I had to get to work!

I'll test drive it Sunday.

Thanks guys,

Karl

[Safety Guy]

Guess I should post how many strokes it took me.

I didn't really count, but it was about 20 to 30 or more.

Yeah, that helps everyone a lot!

Karl

[FestYboy]

sorry, didn't read it through. bench bleeding shouldn't take more than 20 strokes as long as you A) make sure the rubber line seals are tight and not letting fluid out or air back in, and B) pinch the rubber lines off before letting the stroke out. that way there's less of a chance of drawing agitated fluid back into the chamber.