Hi guys, triumph 2500s 1976 having trouble with my brakes, basically on tick over if I push my brake pedal down it goes down almost all the way, but it I build the revs up it works as it should, also, when slowing down to brake, if I leave it in 4th O/D the pedal will travel right down, but pump up on the next press, alternatively if I drop it in to 3rd gear where the revs build, the pedal works fine, the brakes are all new all round, calipers and rear pistons, the master cylinder as been resealed, and iv tried 2 servos and its exactly the same, it's also got new servo valves and servo pipe, any one had similar???