Thread: SIII Stage 1 brake warning switch

hi

i am trying to find some info or a procedure or something on how to test the brake warning switch (the pressure differential one mounted on the chassis). i recently changed the brake fluid on the vehicle and i kind of thought that doing this alone might cause it to trip but nothing happened.

ive checked the electrics of it and they are ok (if i short the wires to earth at the switch the light comes on) so im suspecting its seized or something? anyone got any ideas

cheers

Hello Brendan321

I spent some time playing with mine and can offer the following:

The valve is pretty simple in operation. I have had mine apart and the modes of failure I could see are seizing of the piston or failure if the micro switch.

The micro switch can be removed without loss of fluid as there is a seal either side. I used an inspection mirror once I had removed the switch to check the position of the piston. Some are fitted with a small ball bearing to operate the switch but mine was not. In the end my switch was U/S but as I don't have a warning light anyway I am not too concerned!

Cheers