Coffin Master Cylinder Differences

[ajw85]

What are the differences between these two master cylinders? Notice the different brake switch mounting holes? Is there a way to mount one brake switch on the other?
I've checked the Ducati parts fiches, and they only reference the master cylinder with two brake switch mounting holes for all years...

Below is apparently from a 2005 620


Below is apparently from a 2006 S2R

[Slide Panda]

Same same. The 620 and S2R800 Shared the same brakes up front.

[Howie]

I can't enlighten you on the brake light switch holes, but there are different size masters, 13mm. bore for single disc 4 piston caliper, 16mm. for twin disc 4 piston and 15mm. for twin disc 2 piston.

[Slide Panda]

Reading comprehension fail for me... I had an 05 620 and it did not have holes like that to mount the switch - it looked just like the 2nd one you posted. Besides the differing mount for the swtich, there's some other differences I can see between the two photos. Look at the leading edge of the reservoir - on the top one it's lined up (rough) with the edge of the lever pivot that's closest to the bar, one the 2nd photo that alignment looks to be a lot different. More like it's lined up with the front (furthest from teh bar) edge of that lever pivot... hmmm

[Bones]

i wouldn;t worry so much about the 2 hole vs 1 hole brake light design but rather bore size. that's the critical element.

there's supposed to be a number stamped on the underside to tell you the bore size, but I don;t know how to decipher. perhaps someone could share how to do that b/c I have an extra M/C and I don't know if it will work or not.

[ajw85]

Well I'm worried about the 2 hole vs 1 hole;
I ruined my 2 hole master cylinder and have a 1 hole to replace it.
Now I either figure out what micro switch goes along with the 1 hole or I buy a new 2 hole master cylinder
but
for the benefit of this thread, I'll take a picture of the PN stamping on each master cylinder tonight and post it up

[Bones]

what i'm saying is that the 2 hole switch should mate up. I replaced my 2 hole M/C with a 1 hole and the old microswitch fit just fine.

did you try to mate it up?  


radio shack has replacement switches for cheap if you ruin the old switch.

[ajw85]

Well it looks like the brake switch will mount on both master cylinders, but for the one hole mount, I need to find a longer screw, and I also lost the rubber piece that bridges the gap between the lever and the switch. :-(

[ducpainter]

Well it looks like the brake switch will mount on both master cylinders, but for the one hole mount, I need to find a longer screw, and I also lost the rubber piece that bridges the gap between the lever and the switch. :-(

That little plastic dowel comes with a new switch.

I want to laugh...

but probably shouldn't.

Sorry.

[Speeddog]

FYI:

The diameter of that pin is 0.205", and it's 0.195" long.

[ajw85]

Well my front brake micro switch was toast.
I went to radio shack and picked up that one switch (I'll post a picture later) that just so happened to have a small roller attached to it that fits almost perfectly in the hole to replace the rubber piece. Win.

Yet, I need a longer mounting screw, and I don't understand how this mount functions properly with 1 screw as the switch pivots quite a bit.

So the point of this post: Does anyone know of any local retailers that stock 1mm diameter machine screws about 2cm in length? Home Depot does not and it appears Radio Shack does not either. I figure I will be placing an order with DigiKey soon.

[ajw85]

omg
what the hell is this thing....looking from beneath the handle bars

[Speeddog]

Fixed your pic:

omg
what the hell is this thing....looking from beneath the handle bars

[stopintime]

It's the brake light micro switch.

[He Man]

its a hexagonal nut. and a electronic device that triggers the clutch kill thingy to allow you to start your bike in gear