Soft Brake Pedal - Allroad 2002 2.5 TDI AKE Auto

[ceilidhalfie]

Help please folks. I bleed/replace the fluid every two years. Brakes work fine and fluid reservoir is constant at full level.
However, with the engine off, if I press firmly and constantly on the brake pedal, it travels all the way to the floor. Is this normal? Noticed when after dropping off the car to get the wheels powder coated (will update another post with photos!) when depressing the bake pedal on the courtesy Peugeot 205, it felt like I was going to put it on its nose.

As I am not losing fluid, and am positive there is no air in the pipes (very careful when bleeding/replacing fluid), what could be the problem? - internal corrosion of the master cylinder? - faulty servo unit? - vacuum pump improperly installed (when I changed the cam belts in 2012 - both o-rings were re-newed).

I guessed I have got so used to a soft brake pedal I have not noticed it until now. Doing emergency stops fine and I feel the ABS kicking in.

All suggestions welcome!

[ametlib]

I've experienced the same problem. Dont know what happens but there is air in the system. The way I deal with it is to pressurize the fluid reservoar ( keep it less than 2 bar !!!!) open one of the rear bleed nipples and pump/ bleed using the pedal at the same time

[zollaf]

air can get into the system via the load sensing valve on the rear axle. listen for a squishing sound from this area. bleeding the rear brakes as above will cure it, temporarily at least.