Saxo brake issue

[Rockettvr]

Hi all
I'm struggling to find the answer to a brake issue on my sons saxo 1.1
We've had the car a few months and Tbh the brakes have never been great - needing a lot of pressure on the pedal to get any braking response. A couple of weeks back the brakes went altogether - master cylinder failure. A new one ordered and fitted, bled the brakes but found a failed slave on one of the rear drums(probably why the brakes have never been good) Fitted new slave , bled brakes again but the rear drums are not working correctly - the fronts are great locking up when the pedal is pushed but the rears barely have any grab to them - even when the pedal is pushed fully down I can turn the wheels by hand although with some effort.
I've bled the system several times using an easy bleed non return tube , the brake shoes(renewed both sides when slave replaced) are adjusted as far as possible without actually rubbing and the hand brake works really well needing only 3 clicks to lock the wheels solid.
I've had the drums off and the slave cylinders expand when the brake pedal is depressed
I thought it may be a faulty master cylinder (although new) so fitted another but the same symptoms persist.
In short the brakes are working well except that the master cylinder is exerting some but not enough pressure to the rear wheel cylinders.
Am I missing something ???
Any thoughts gratefully received
Thanks Ron

[megamaniac]

Ratchet style adjuster or turn adjuster? Did you back the handbrake cables off before you adjusted the shoes? Also sometimes the dust seals on wheel cylinders can be too strong and pull the pistons away from the shoes resulting in a long pedal that comes up with a pump.

[Hammer67]

Does the car have a load valve fitted? Usually found on the rear axle that apportions brake pressure front/back in relation to vehicle loading. Will have the hard pipes screwed in and, usually, a large spring attached.

If it has, sounds like it may have failed.