Riding home from work tonight for some reason thought I'd try the rear brake with a bit of effort (as I normally only use it at low speeds) 'just to see that it still works'.
Only going ca. 10 mph I pressed pedal and rear locked up (ABS did not appear to activate - maybe too low speed?). I did this twice and then carried on...a couple of hundred yards later decelerating for a junction the bike started to slow down by itself!
Rear brake was was on and pads smoking.
Hmmm - I released the pressure via the bleed nipple which obviously released the piston pressure. Tried brake again but nothing so went home whilst learning to use just front brake in traffic which was a bit alien until I go used to it.
Read up about the ABS system when home and investigated a bit more. The symptoms are as follows; pumping the lever does apply the brake pads progressively (albeit slowly) but it is like there is a non-return valve in the system as the pressure does not relieve and the brake just gets tighter and tighter
Looking at the detail in the service manual all I can assume is that the ABS spool valve is stuck in the emergency braking position so that the fluid flow from the master cylinder is going via the orifice - that said I'd expect the pressure to still release. As I said the it's like there is a non return valve. Also the valve spool in the block appears to be in the de-energised position (i.e. you can push it in by hand - which makes no difference incidentally).
There is no ABS warning light lit and the front brake works as normal (including ABS function - I tried it on gravel track opposite my house).
Anyone got any ideas?
Update 21-Aug:
took in to JAX motrocycles in York (Yam dealer) - they confirmed that there is a fault internally in the ABS hydraulic/pump unit - rear brake would not bleed through the hydraulic unit - new replacement ca. £700! Their suggestion is to convert to 'standard' and junk the ABS unit as cost is prohibitive.
Update 22-Aug:
hydraulic unit is fooked - cannot bleed through it - I've tried everything - looking on a FJR forum the diagnostics cannot detect a spool failure - I've used the test connection to run the diagnostics as per the service manual - all good (but obviously isn't!) - can't find a 2nd hand unit (well other than one in Denmark for £500 - so going to convert to 'non ABS' (ordered the HEL lines today) - BTW new unit is over £1,200!
