I agree.
And if lazylunatic hasnt got the correct one way valve (non return valve) like he said 'used a silicone pipe'... your bound to be getting crap into your servo which to me is very dangerous.
put it this way its not good when you brake hard and your servo pops and your pedal goes absolutely solid and starts hissing air. which then stalls your car.
Lazylunatic - Look further into this if i was you mate.
Christo