We've never had what I could call a good footbrake.  Have bled it to death but came to conclusion that master cylinder must be suspect.  Have no replaced the master cylinder with a new item and while at it have replaced all the rubber brake hoses with stainless braided hoses.  Net result is no change, have an OK pedal with no ignition but as soon as the servo kicks in the pedal goes to the floor.  Am at wits end, calipers are fine, discs and pads are fresh, rears are adjusted, no leaks from the system that I can find.  

Given the servo may be being a bit too enthusiastic, just wanted to ask whether the upgrade to the 1.8 increases the vacuum action on the servo?  Is this something that anyone else has encountered or is it something I should have known about and fixed??

Any other suggestions in general appreciated.

Cross corners still, though something to double check I spose as I re-routed the brakelines to the rear internally so as to allow a hydraulic handbrake (which isnt fitted, just bypassed).

Brake lines were picked up at the bulkhead and routed internally along the exhaust tunnel, back out behind the cable handbrake and replaced the lines back to the flexi hoses to the drums.  Hydraulic HB is inline but isnt installed at the minute, have just a blank pipe on each line where it would feed in/out of the h/b master cylinders.

Hard to know what could have gone wrong given its OEM apart from the brakelines which are just a different route between 2 points.

Re the valves / front rear splits on the bulkhead - is there any adjustment in these in terms of how much pressure is sent to the rear?  If I get standard brakes up to standard my intention is to plumb the hydraulic h/b back in, but that will probably need to include a bias valve on the lines to the rear so as to minimise effort lost in taking up slack in the h/b master cylinders - it'd be good to know if this could be done with the existing valves?