perfection

Crazy noise like a bird dying / baby crying is being emmitted from brake booster area.

This goes on and off.

Then after about 15 mins of driving it "flatlines".

Just goes Beeeeeeeeepppppp continuosly and all the lights come up, eg. VSC / ABS / Handbrake etcetc.

Actual brakes? FINE! No loss of pressure / pedal feel etc.

PLEASE HELP! There must be a sneaky trick to fixing this or something?

So far I have...

Bled the brakes twice.

Bought 2nd hand all the electonic brake components etc and replaced all except for the master cylinder.

Have had the electronic reset tool reset the system.

Bled the brakes again. Disconnected the battery to try and reset the faults in the computer. etc.

I am totally at a loss and am going to have to sell the car for a loss if I can't resolve!

Ps. car is a local 1998 and has genuine 42,000klms only!!!

Any advice / contacts / suggestions appreciated. I've had this car off the road for a month trying to fix her!