Air in Hydraulics

[rogerowen]

I've just replaced all wheel cylinders and 2 of the brake pipes that looked a bit iffy, but every time I bleed the system a tiny bit of air keeps appearing at the last point (front O/S). I can't see any leaks - but as I press the brake pedal there's a bit of commotion at the neck of the master cylinder (not sure if this is normal). After bleeding, the pedal travels too far on first push but is better after several pushes. Any ideas??? Thanks.

[C6Dave]

Worn seal on the piston on the master cylinder?

[mike.perry]

Have you adjusted all the brakes?

[bmcecosse]

Adjust the brakes up hard - then bleed. The master is fine.

[Alex'n'Ane]

"a bit of commotion at the neck of the master cylinder" What do you mean by this? There is a rubber sleeve/hat/seal that moves when the pushrod goes from the pedal, into the mc. You will also get a little spit of fluid popping slightly at the surface of the mc if your looking at the fluid? Also maybe you are loosening that bleed nipple too much, and letting air in there. Just try bleeding it, ending at a different point, and see how it goes? Its not vital you do it in the 'correct order'.

[rogerowen]

Brakes are adjusted to maximum on then back off 1 click to free the wheels. Popping or spitting is the 'commotion' that's happening as I press the pedal looking down at the fluid.

[PSL184]

Brakes are adjusted to maximum on then back off 1 click to free the wheels. Popping or spitting is the 'commotion' that's happening as I press the pedal looking down at the fluid.

Fluid out the m/c is normal.... Thats why there is a cap on it
Brakes should be up tight (wheels locked) to bleed then back off one notch on adjuster after bleeding.

[rogerowen]

Thanks all for advise, will try the recommendations.

[aupickup]

the front brakes hav two cylinders, so can not lockup both of them,

[bmcecosse]

You can make one v tight - then turn the drum 180 to the next one........

[aupickup]

ah ok thanks