td5 with dodgy brakes !

Hi
the brakes on my early td5 (non abs) have have started to require a fair bit of pumping before they work, when you get the pressure up they work fine but soon lose the pressure again so the pedal will go to the floor also the brake warning light (also the handbrake light) has stopped going off when the handbrake is released but after some hard pumps will go off only to flicker back on after a minute or so. i have done a search for this and come up with a few suggestions; dodgy wheel bearings which i can rue out because they have been replaced and the master cylinder.
but i dont know what to look for from the master cylinder, the reservoir is still full and there are no leaking pipes anywhere on the truck, i removed the cylinder from the servo and there was no sign of any leaks out of the back of it, does anyone have any ideas please ?

Only thing I can suggest from your symtons is there is a leak some where.
All you can do is check and check again. You don't say if its losing fluid - Maybe sucking air in but the fact that the light is on says it's loosing fluid.
Good luck mate

Ah sorry meant to say there has been no loss of fluid, does the warning light only show for low fluid level? does it have any other sensors ? thanks

sounds like seals u/s in master cylinder

Not 100% sure about TD5 but as a general rule it's a low fluid light unless the Td5 has a low pad sensor too???
I agree with Uncle albert. Sounds like M/c Seals now

flickering light on a td5 can be dodgy connection at the handbrake, low fluid level, pad sensor if fitted, or in the fluid reservior cap there are 2 electric contacts that corode, if you pull the rubber seal out of cap and scrub them with a scothbrite pad soaked in clean break fluid, that should clean them up,
my brakes need pumping when wheel bearings need changing