I had to pull up sharpish yesterday in my 2000 Hiace van after a dodderer pulled out. My brakes felt rubbish and I only just stopped in time. Afterwards they seemed to go back to normal, but the brake warning light has been flickering on and off occasionally since then. I took it to a local independent garage today who checked the fluid, pads, shoes and handbrake switch, which were all good, right level and all working fine, but the light still comes on occasionally, which worries me particularly after the poor braking incident.

Page 135 of the owner's handbook refers to the tandem master cylinder where, if either sub-system fails, you get the symptom I described, plus the brake warning light comes on. Perhaps it's this, but the garage tells me the brakes are fine. It could be a wiring fault, but I'm not convinced. Any ideas?