brakelight problems

[Cybermunster]

I'm experiencing the following on my 92 907
It has new pads (EBC) front/rear and new Galfer braided lines front/rear.

Problem is the rear brakelight will not come on unless you depress the pedal all the way and then some more, it's like the light wont come on until you almost lock the rear brake, the front is also similar in that a lot of brake pressure has to be excerted for the light to come on.

Any ideas, suggestions?

Thanks

[Laddie907]

front & rear systems are switched by different methods.

I don't think the new lines will have any effect on the rear.

the rear is switched at the master cylinder with a hydraulic switch (top) operated by pressure in the master cylinder.
normally only fairly light pressure is required to operate it
if it operates at all at very least this says you're getting hydraulic pressure thru...
I know braided or Kevlar lines give better feel, less spongey - but the line pressure to operate the caliper is the same. The switch should still get roughly the same line pressure as before.
the pressure required to brake effectively might change a bit with the better pads - I dunno, is the braking that much discernably better???
you might need to see if the switch is filled with crap?
this might restrict hydraulic delivery to the switch?
you can disregard electrical fault.

the front switching is done with a mechanical microswitch under the lever assembly.
I can see this switch position might change with better lines and pads...
basically - you just need to reset the throw distance for the switch at the lever and probably have to grind a bit off the pin - trial and error...
I can't see any other adjustment method.

[ducapaso]

I'm experiencing the following on my 92 907
It has new pads (EBC) front/rear and new Galfer braided lines front/rear.

Problem is the rear brakelight will not come on unless you depress the pedal all the way and then some more, it's like the light wont come on until you almost lock the rear brake,

Maybe new pads and pipeline have improoved too mutch braking power?

[Finnpaso]

There is only simple pressure switch in back brake system..... There is also simple adjustment in that brake lever pin, that You can adjust that lever.... i hope, You managed

Front brake switch: You can make easily new plastic pin inside that small hole between micro switch and lever. That lenght of that plastic pin make just that adjustment , when Your brake light comes on and off !!!! ..and now... ..then

[Tigger]

Maybe new pads and pipeline have improoved too mutch braking power?

can you have too much braking power!!

If you want to replace the rear pressure switch, the part will be stocked by loads of people as it is used by the racing guys for data-logging the rear brake info, and Brembo systems are still very much favoured. Make sure that you get a pressure switch to fit a brembo system as they use unusual sizes. My switch went a little while ago and replacement was easy.

Regards

Bryn

[andrew_b]

I had mine serviced last week and have been experiencing similar problems. Front brakes not activating the stop light and rear only with significant pressure. I started troubleshooting at the electrical end of possibilities since I figured a fault in both different front and rear systems at exactly the same time was pretty unlikely.

I discovered that I'm getting at least 1.1V drop from the front brake switch to the loom junction at the tail light assembly. This is about 0.3V more than the rear brake switch at the same point, and both drop even more at the lamps themselves...even after cleaning the connectors.

Solution, and maybe it's just a stop gap, I've added a relay at the last loom junction and now I have perfectly operating brake lights. I pulled battery voltage from the fuse block and spliced the relay into the signal wire from the main loom to the tail light. The front switch works perfectly and the rear pressure switch is now fairly sensitive. I can light up the tail without hardly dragging the rear brake - it is that sensitive.

So unless anyone can see a problem I'm missing (and I sure hope this isn't a sign the whole shooting match need rewiring!!) I'd suggest trying the relay mod and see if it works for you too.

Cheers
Andrew

[Finnpaso]

Those relay mods are good, if there is some voltage drops in circuits, or too small diameter wires in circuits. Voltage drops can come from bad groundings, dirty connectors, too small wires, etc..... I have added to my 750 Paso 4 extra relays and to my 907IE 2 relays and i have been happy since.... Anyway with that small plastic piston (lenght) between f.brake lever and micro switch you can adjust that swithing point of brake light. Only find suitable plastic and cut it right lenght.

[andrew_b]

Hi Antti, Where else did you need a relay on your 907?

Cheers

[Finnpaso]

I put dual headlight kit from Gagiva Elephant 900GT to my 907IE, so then i added one for low beam and one for high beam. btw, looks "cool"

[andrew_b]

Hey guys - anyone have a source for the microswitch on the front brake assembly - mine has evidently given up working.

TIA

Andrew

[Finnpaso]

I find some spare for me from local electonic shop, but have to choose "NC type", what have pins closed, when pull lever (or micro switch is in free space). Cheaply!

Btw, be carefull with that small plastic pin inside lever system, that it wont get lost !!!!!!

[higgy]

Try Bevel Heaven or California Cycle works or Desmo Times

Desmo Times is in Pensecola

[andrew_b]

Hi guys, I did without a working front brake light for a while when I found desmotimes wanted $38 for what didn't even look like the right part!!!

I have just found the right one though - it's the same switch used on BMW 650s and some old Guzzis.

Here's the info www.happcontrols.com, Part # 95-0863-00, Cherry DC-1 waterproof and dustproof microswitch.

Anyway they were $2.35 each but min order of $25 online - so I just went ahead and bought a lifetime supply

So, if anyone needs a microswitch for their front brakes I have plenty spare and will be happy to mail you one!

Cheers
Andrew