5 replies to this topic

[pete l]

Hi all

Just installing my rear brake cylinders and thought "that's wrong"
The bleed nipple should be at the highest point, air rises, the bleed nipple is actually at the lowest point. How are we supposed to get all the air out?

Pete.

[DeadSquare]

I wouldn't worry too much. 

 

Because of the "Hydraulic pressure regulating valve", the rear hydraulic brakes don't do much, and are only useful for "Left foot braking" when cornering.

[Ethel]

If they're new cylinders you could potentially bleed them by loosening the pipe unions. They seem to bleed ok though. Guess  there's insufficient space between the pistons to trap air against the flow. 

[Spider]

Ideally yes, it should be at the top. I did in fact look once at turning them around, but they'd be a mongrel to bleed.

[mini-mad-mark]

It just seems to work.....

 

Sorry I cant offer a scientific explanation but my layman's thought is related to the post above - there isn't much space in the cylinder so once you open the  bleed screw it just fills up and the air is forced out as there isn't anywhere for it to sit.

 

I have "manually" bled rear brakes by just opening the bleed screw and waiting for a steady flow of fluid then locking them off and that seems to work OK.

[bpirie1000]

Think of it like this.. the cylinder is lowest point..

Master cylinder is highest point. Bubble will always go upwards.
Brake fluid is not compressible really and as such....

The fluid flows down the hard lines and bleeding the brakes merely takes the bubbles out quicker than gravity will.

You can gravity bleedmbrakes. Leve them a slightest bit loose and then just play the waiting game.. when you think that system is full and all bubbles have soaked to the master cylinder... then, and only then will you have a good tight pedal.

Bleed nipples just said up the process really. They take the air bubbles out from the lowest point.....they also help brake system being full have a fullmsystem and