Sorry Paul tohear you are still without brakes. The likely hood that the repacement servo is duff is very UNLIKELY, although I must admit I felt the Master cylinder was your problem rather than the servo.

I assume you have tried a normal tubing without the non return valve in situ. with the same results?

I'm now thinking of the mechanical connection of the pedal to the push rod as you are obviously no longer getting air within the Master cylinder or from the system when you bleed it.

As far as I am aware the vacuum is taken direct from the inlet manifold without any adjuster or valve. I will have a look at my Manual and add an edit to this if I find anything or not as I am scratching for solutions.

I don't think Kwik Fit will solve your problems.

OLDMINIMAN

Hi Paul

If you start the engine and then switch it of can you hear the sound of the servo operating and exhausting its pressure? If not then the servo is not functioning. An additional test to confirm will be to press the pedal and start the engine. You should feel a slight rise in the pedal as the servo licks in. If not then the servo is duff.

The servo is quite a complicated array of springs, "O"rings, seals and valves and I would suggest that you have a workshop manual before you commence dismanteling.
(SST = SPECIAL SERVICE TOOL)
The manual refers to an adjustment using a pressure guage and a SST tool09737-87001 to set the clearance between the servo push rod and the master cylinder. You first apply the tool squarely to the rear of the master cylinder and adjust the centre bolt until it squarely makes contact with the end of the Master cylinder push rod. Place the tool then on the face of the servo and endure that the distance between the centre bolt and the end of the Servo push rod is zero. To adjust the servo's push rod, loosen the lock nut and turn the adjusting nut whilst keeping the rod fixed until the desired clearance between the tool and the rod of ZERO is achieved and the tighten the lock nut to 20.4-30.6N.m (2.08 - 3.12 kgf-m or 15.1 - 22.5 ft-lb)

If you look at the Servo from the side it's push rod appears from the diagram to be ahead of the front face of the servo and thus the distance between that and the operating push rod of the master would be minimal or zero.

The sst is a simple H shape with the lower legs longer and no wider than the end of the rear face of the master cylinder. It is drilled and tapped dead centre of the H cross bar and then a bolt the same length as the sides of the H is screwed into the H. The SST is then placed on the Master Cylinder and the centre bolt screwed in until it makes contact with the plunger rear face in the master cylinder. The bolt will then protrude beyond the feet of the H.

The SST is then placed on to the Servo face but up the opposite way so that the head of the bolt is nor facing the push ros coming out of the servo. The rod is then adjusted as detailed above untill the distance between the rofd and the head of the bolt on your SST is ZERO.

Note whilst making the the adjustment the gasket for the master cylinder must be in place and thea negative pressure of 500 mm hg should be applied to the sevo using a MITYVAC or the like.

I am reading and translating from the manual and was I to do the job would probably have the engine running to achieve the negative pressure and then do the adjustment.

The effect of this is to remove any excess movement from the servo actuating rod and the master cylinder push rod. With the amount of play you have it sounds as if part of the serve may be either missing or the gap between the rod and master cylinder huge.

Paul I am more than willing to send you the booklet on the brakes from the manual for you to copy in the knowledge that you will return it to me. Let me know and I will get it posted this weekend. It shows the complete system in detail and is from the complets Daihatsu Sportrak manual prodeced by them. Translation from Japanesse to English is hit and miss in parts but not too bad. The adjustment cannot be made from the clevis pin rod as this is not part of the same push rod that comes out of the front of the servo. The clevis pin rod pushes onto the servo push rod which inturn pushes onto the master cylinder push rodwith the assistance of the servo booster spring.

There is also a chapter on Proportioniong the BYPASS valve that ensures that a lowere hydraulic pressure is applied to the rear wheel and how to adjust that item.

OLDMINIMAN