How to: Bleeding The Brakes

[TwinLewi]

Question that just came to mind.
I have removed the master cylinder. Removed caliper to replace with new one because original one shows to much rust behind piston. Also can’t get bleeder side piston out. It is pressed in really far. Caliper is way to rusted inside for new seals and pistons.
I removed the brake lines and installed new ones.
So is my procedure the same as I have read on here to bleed? Or is there a different method for all new parts and lines? Maybe you would want to place fluid in a syringe with a hose on it and press fluid in through the bleeder screw on the caliper since air rises best. Thoughts?

 

[gggGary]

Yes many ways to bleed, none perfect but bottom up is good. I tried a squirt oil can via hose to the bleeder one time but think the seals in the can didn't like brake fluid.
one tip is to leave the caliper off, don't install pads til AFTER you have done most of the bleeding. some sort of lever, steel bar tween the pistons so they can be pressed in AND levered back out a few times really helps get ALL the air out of the system. also keeps from getting fluid on new pads.

 

[5twins]

Maybe I've just been lucky but I don't encounter many brake bleeding issues. The last couple systems I've done were totally dry to start. They were renovated calipers and master cylinders with new stainless lines. I have one of those MityVac vacuum pumps and start with that. That rather quickly pulls fluid through and fills the system. Once I've got fluid flowing through, I draw a couple full reservoir's worth through and by then I'm usually getting some lever pressure. Once I start getting some lever pressure, I switch to the normal bleeding method (hand pump lever, open bleeder valve) to finish the job.

My little tip - you can often free up air bubbles in the MC by squeezing the lever and letting it snap back open. Do this multiple times and watch the fluid in the reservoir as you're doing it. You will often see air bubbles released and floating up out of the ports.

 

[TwinLewi]

Cool. I am thinking now I will get a syringe and pump fluid into the lines to speed the process up. They’re on the bike already but I will fill until fluid drips out the bottom line.I have three lines. Upper and lower rubber then the metal line that attaches to the caliper. (Bench bleed M/C) install that to the bars with it level. Connect line to it. Install caliper on fork. Then bleed using the old pump method by lever. Burping banjo bolt and other junctions. Great tip GGGgary on removing the pads. I have some old ones laying around with a bunch of meat left on them that I could install for the bleed purpose. Then install new ones afterwards.

 

[TwinLewi]

Okay! I have a good working brake! It drags on the rotor a bit but it works good in the lever.

 

[Bruno_c]

My method with a bicycle pump.