Brakes - what brakes!!

Hi all, i recently purchased a land rover series 2a 1967, lovely car - needs some tlc but goes well. unfortunately it doesn't stop so week! the brakes don't work. when i depress the brake pedal it stays down and the brakes work for a bit and then stop working - quite disconcerting. The slave cylinders all appear to be working ok and i suspect the problem is in the servo or the brake failure valve. Has any one experienced something like this before. Any help valued before i start stripping the whole system.

go to the introduce yourself section before the old guard come and take the **** !

You are going to have to strip the system (drums off) to start

Brakes are pretty critical so if you think it may be over your head take it somewhere to be done

not quickfit,
If you post your location some one will no doubt recommend somewhere