Hi to all you tech people
This maybe a silly question but is there any other way
other than the master cylinder, that the system can
draw in air?
Cheers Mark.

Wheel cylinder seals leaking, perished brake hoses, rusted through brake pipe, caliper seals perished, seals between m/c and reservoir and the m/c can be rusted through and leaking in to the servo.

Also the fluid can get locked in the resevoir if the seals between the resevoir and master cylinder have flowed into the master cylinder blocking the fluid entry.

On the 360 its can also feel like air if the rear adjuster is not quite working right, mine are still a bit intermittent, even though all clean and assembled correct AFAIK.

Ahhh, the good old 360 brake pedal which goes 90 percent to the floor......

Ride_on wrote:On the 360 its can also feel like air if the rear adjuster is not quite working right, mine are still a bit intermittent, even though all clean and assembled correct AFAIK.

I didn't know this, might be worth taking a look at the adjuster on my 84.

Just get on and bleed them, you know it makes all the difference.