brake problems

[davidwil]

My Disco 3 TDV6 2.7 has had a parking brake problem for a few months due to dust, but we've successfully avoided using the parking brake until our service manager works out how to fix it.
This morning, starting was difficult due to a flattish battery and a 'park brake fault' showed briefly. We had the battery replaced. This afternoon, the engine would not turn off until I released the footbrake (no matter the position of the key) and pushing on the footbrake (even with the key out) would cause the dashboard 'starting sequence' lights to come on. The Disco would drive OK.
This evening, as well, the parking brake is locked on and the rear brake lights will not extinguish. The 'park brake fault' error now shows.
Any thoughts would be helpful, otherwise NRMA Premium will get a call in the morning.
thanks
David
Follow-up:
Disconnecting the battery for 15 minutes solved the footbrake and brake lights problems (thanks BobZ) but the 'park brake fault' remains.

[the_preacher1973]

I realise it's probably too late but Robert Pepper posted a pretty neat guide for manually releasing the EPB when it eventually fails:

Releasing the park brake on a Discovery 3/4 | 4WD Book & 4X4 News (http://www.4wdhandbook.com/rmp/blog/D3-D3-park-brake-problem-release)

Worthwhile keeping a screwdriver and pliers in the car for just such an occasion.

[DiscoWeb]

Worthwhile keeping a screwdriver and pliers in the car for just such an occasion.

Or simply use the hook end from the jack winding arm to manually release the EPB. This has worked for me.

George

[davidwil]

Thanks for the replies.
I had manually released the brake using the lift handle but it re-engaged as soon as I tried to move off. Anyway, the Disco's in hospital now.
Davidwil