Audi A4 2002 1.9TDI Brake problem - Please help - emergency stop Brake pedal goes hard and brakes not working

[PaulCsordas]

I have recently had a full service on the car about 1000 miles ago.
The rear brake calipers had partially seized so these were removed and cleaned and freed, along with new pads and the discs had been lightly skimmed.
All fine until today when driving down a country lane and had to apply quick braking. The brake pedal went hard and the car did not stop immediately.
I pumped the brakes several times and initially the pedal stayed hard. I switched off the engine and then repeatedly pumped the brakes. The brakes were more bouncy but when I pushed the brake pedal firmly again it went hard like before.
It's difficult to say if the brake feels normal now so i need help and advice please.
What might be going on here and is it dangerous to drive like this, I have a 4 and a half year old son and i am not putting him in harms way.

Any help will be hugely appreciated!

Many thanks

Paul

[arman123]

Check you plenum chamber for water just by the Brake servo and under battery if there is standing water there then this gets sucked up by the brake servo and you loose brakes over time if it's been left too long it can rust the inside of servo then it will need replacing also check all pipes coming off servo for damage there are bungs under servo and battery that many people remove so water goes straight out check that first then get your brakes checked over by a garage

[PaulCsordas]

Many thanks for the advice.
I will check out and rectify if there is water there.

[trevor simpson]

Hi . First check the vacuum hoses to the servo .It might be something very simple this has happened to me .
Regards Trevor.

[PaulCsordas]

Many thanks Trevor, I will tell a look?
Best regards,
Paul