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bleeding brakes top to bottom

Jake14

Well Known Member
Upgrading the brakes from the low (162k ft-lbs, 1/4in disc) energy to higher energy (dual piston 246k ft-lb, .375in disc), but have a question re bleeding. In my car days we always bled the brakes at the wheel cylinders by pumping and holding the pedal, but all I've seen on VAF is bleeding bottom to top. Is it ok to just cap off the line when removing the old caliper and bleed the air out using the brake pedal after installing the new caliper or does this risk entrapping some air?
 
I replaced the O rings in the slaves and was successful with capping off the line, filling the cyl's, installing the pistons and pressing them to flush with the housing and connecting the line with a small dribble from the master. In my case, no bleeding was needed after the installation. Be sure to start off with a full reservoir.

If you don't introduce any air into the system in or before the masters, you should be able to bleed from the top down.
 
For my Dos Centavos, bleeding from the bottom up is very simple, and has worked every time for me.

Just make sure that all the brake pedals are fully retracted, and have an overflow hose from the reservoir. It can be a one-person job.

I use a cheap plastic sprayer from the aviation department at Home Depot, and attach hoses to it as needed.

YMMV
 
I'm a bottom to top guy. So easy it's funny. Especially If you make a fitting for the top of the master reservoir to catch the overflow.
Art
 
Really?

I'm a bottom to top guy. So easy it's funny. Especially If you make a fitting for the top of the master reservoir to catch the overflow.
Art

The bubbles get a tailwind going bottom to top. :D I will still do my cars from top to bottom though.

Assorted reasons for aircraft being different.
Why top down on ground vehicles?
bleeders on the top - - my RV is on the bottom
iron calipers/wheel cylinders/master are first to corrode - My RV has aluminum caliper/master
corollary: cleanest fluid pushed into system.
Also- hygroscopic fluids not used on RV's
 
bleeder location

On most cars the bleeder is on the top of the wheel cylinder. On most airplanes the bleeder is on the bottom of the wheel cylinder. That should be a clue on how you need to bleed each.
 
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