When should the brake light switch operate. When the pedal is initially depressed or further on into its travel?
It’s not split second quick But should light as soon as The pushrod on the master cylinder moves They are a pressure switch
Depends on how much free play there is on the pedal - you may push it a way before the pushrod on the MC even moves
My brake light is not coming on until the pedal is fully depressed. Would that be a px switch issue or something I could adjust on the pedal?
How far down is your pedal moving? Implies you’re not building up enough pressure to operate the switch (or the brakes )
The pedal moves fine and I can feel good positive pressure with increased range. There’s no issue with stopping my brakes are very good. However if anyone is behind me it would appear they can only tell I am slowing down if I slam on the brakes.
This is normally a symptom of a failing pressure switch Unfortunately the replacements that are available seem to be of poor quality
That will be because the brake lights are dim and they only spot it when the back end of the bus goes up in the air and the gap suddenly decreases. Modern drivers look at the high level lights more these days I think. So I made and fitted one in the bottom of the rear window. If you are running with recent rear lamp clusters they don't have reflectors. Taking out the bulbs, mask off the sockets and spray inside with silver or white paint. Change the bulbs if the old ones look blackened. LED bulbs are brighter (not type approved might fail MOT, my LEDs never have) make sure you get the versions with LEDs firing backwards as there is no reflector for side firing LED chips... Check the switch . If you have no friends back up to a white wall or door in the bus in the dark or twilight.. and press the pedal.. you will see reflections as the lights work.
That’s a typical problem with hydraulic brake light switches and one of the reasons why I modified mine to operate off the pedal – as soon as the pedal moves the brake lights come on. You could try renewing the existing switch but it might not be better.
Three pin are NLA from VW, just fit the 2 pin unless you need a light to tell you your brake pedal has gone to the floor.
Thanks for the replies. Looking on heritage that part number is £5.75 so that’s not too bad. I take it heritage ones are ok. Any other sources ok?
Try cleaning the connectors and the wiring, wd40 into the connectors can help too, the switch operates on pressure and resistance so more resistance in the connectors etc will result in a slower switching time, could be a dodgy pressure switch but as above, replacements are questionable
