My rear brake switch seems to be malfunctioning.

Either it is the switch itself or there might be a break in the line towards the brake light.

So this has me wondering what the easiest way is to check where the fault lies. And also whether there is a way to replace the switch without having to go through the process of replacing the brake fluid and getting all the air out of the system again?

The switch is completely separate from the hydraulic line
Should be easy to get it off, just a couple of plastic nuts on the body and UNplug it

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you win some, lose some, crash some
K+N filter, snorkel removed, homemade kev mod (with his blessing), co raised,
Pipeworx cans, r1 led back light, under tray removed, small indicators, handguards, cnc short levers,

It is on X and R, but not on the Z - the switch assembly is the banjo bolt.

Quickest way to get a ball park idea of what's wrong is to unplug the connector to the brake light switch and use a multimeter to check continuity on the switch side (and switch function) with brake on/off.

Test the tail lamp by applying 12v to the green/yellow wire on the lamp side of the connector to test stop light LEDs. (Brown is +12v supply to switch and green yellow is feed from switch to stop lamp)

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Thanks for the info. I'll try that. If it turns out to be on the switch side of the wiring I'll just have to bite the bullet and replace the whole thing and take the opportunity to put some fresh brake fluid in.

My bad, didn't notice was in the z section
What a stupid idea, for a off roader, rip the switch off and possibly lose the rear brake

__________________
you win some, lose some, crash some
K+N filter, snorkel removed, homemade kev mod (with his blessing), co raised,
Pipeworx cans, r1 led back light, under tray removed, small indicators, handguards, cnc short levers,

Would never really happen.

Pressure/banjo switches are much more common on dirt bikes IME than on street bikes. Probably because they can't get full of dirt and jam up.

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I spent a lot of money on travel and racing motorcycles - the rest I just squandered.

XT660Z - Commuter, Adventurer...Racer?

www.dashmoto.net

Other bikes >> MT-03 / CG125BR-J / ER-6F
Departed >> ZXR400L3 / EC300 / DR-Z400E / DR800S / GPZ500S / GS400