Front master cylinder removal

Energy One

SBMike

Member
2007 K-9. I’m going to rebuild the front master cylinder because the spring must be broke. I’ve got the mirror off, took the 2 bolts that hold it together with the switches on the front side, but I can’t figure out how to remove the wire which must be for the brake light. It looks like it’s soldered next to the microchip. I figured before I screw something up I better ask. I searched and came up with a post from 2009 that suppose to tell how but it said it was removed. Thanks
 

knothead

Second Chance Customs
Yes that wire is your brake switch and its attached to a magnet....if you look close on the bottom side of the control directly under where the magnet is there is a set screw....its a .050 allen best of my memory...back it out and the magnet should come out....it may be stuck with silcone so you may have to spray with wd 40 or carburetor cleaner and it soften the silicone and come out....be careful not to pull on the wire very much or you will screw the magnet and wires up ....also if you look up in the cavity where the brake lever was you and see the magnet sticking out a little bit....you can spray around there to and let it set for a few minutes before trying to get it out if it is actually stuck in there
 

SBMike

Member
Yes that wire is your brake switch and its attached to a magnet....if you look close on the bottom side of the control directly under where the magnet is there is a set screw....its a .050 allen best of my memory...back it out and the magnet should come out....it may be stuck with silcone so you may have to spray with wd 40 or carburetor cleaner and it soften the silicone and come out....be careful not to pull on the wire very much or you will screw the magnet and wires up ....also if you look up in the cavity where the brake lever was you and see the magnet sticking out a little bit....you can spray around there to and let it set for a few minutes before trying to get it out if it is actually stuck in there
Ty ty ty. Yes it’s 0.50. I’m finally free lol. My front brakes work fine other than the handle doesn’t return all the way. There’s just enough slack that when the wind hits the handle it goes back and is just enough to keep the brake lights on. So I figure the spring is broke. And from what I read you might as well use the whole rebuild kit since you’re there. That screw looked like a set screw but I put the smallest Allen I could find in it and it didn’t feel like an Allen. I put the calipers on the 6 Allen’s I was trying and they were all .058 to .068. I dig deeper in the drawer and found a .050 and went right in and wasn’t stuck. Wire and magnet slipped right out. Thank you again for the quick response.
 

SBMike

Member
Ty ty ty. Yes it’s 0.50. I’m finally free lol. My front brakes work fine other than the handle doesn’t return all the way. There’s just enough slack that when the wind hits the handle it goes back and is just enough to keep the brake lights on. So I figure the spring is broke. And from what I read you might as well use the whole rebuild kit since you’re there. That screw looked like a set screw but I put the smallest Allen I could find in it and it didn’t feel like an Allen. I put the calipers on the 6 Allen’s I was trying and they were all .058 to .068. I dig deeper in the drawer and found a .050 and went right in and wasn’t stuck. Wire and magnet slipped right out. Thank you again for the quick response.
.050 not .50 lol
 

HMAN

I just like my Freedom
Supporting Member
Are the crush washers on the banjo bolts a standard item? Can I get them at an auto parts store? Or Harley dealer?
I got a box of assorted sizes @ Harbor Freight. They work like a charm. They are common copper crush washers. Parts store should have em as well.
 

knothead

Second Chance Customs
Ty ty ty. Yes it’s 0.50. I’m finally free lol. My front brakes work fine other than the handle doesn’t return all the way. There’s just enough slack that when the wind hits the handle it goes back and is just enough to keep the brake lights on. So I figure the spring is broke. And from what I read you might as well use the whole rebuild kit since you’re there. That screw looked like a set screw but I put the smallest Allen I could find in it and it didn’t feel like an Allen. I put the calipers on the 6 Allen’s I was trying and they were all .058 to .068. I dig deeper in the drawer and found a .050 and went right in and wasn’t stuck. Wire and magnet slipped right out. Thank you again for the quick response.
No problem buddy thats why we are here to help eachother if and when we can
 

mleach72

Well-Known Member
There is a set screw in the front part of the control to keep the control from turning on the handlebar. Remember to loosen it up before putting the control back together. If you don't, it will make it slightly difficult to get things lined up. Plus, it just makes things easier to get the control where you want it. You can tighten the bolts holding the two halves together and you should still be able to turn the control. Get it where you want it, then tighten the set screw.
 

SBMike

Member
I got a box of assorted sizes @ Harbor Freight. They work like a charm. They are common copper crush washers. Parts store should have em as well.
I picked up the washers from harbor freight but there was 2 in to rebuild kit.
 

SBMike

Member
There is a set screw in the front part of the control to keep the control from turning on the handlebar. Remember to loosen it up before putting the control back together. If you don't, it will make it slightly difficult to get things lined up. Plus, it just makes things easier to get the control where you want it. You can tighten the bolts holding the two halves together and you should still be able to turn the control. Get it where you want it, then tighten the set screw.
When I took it apart I seen that screw and wondered what it was for. It didn’t seem to go to anything lol. I got it all put back together and it works great. The spring wasn’t broke. The piston was just super tight in the bore and wouldn’t move easily. I did break the reed switch putting it back together though. I’m assuming I’ll need to buy the new board with the buttons. So now my brakes work awesome but no brake light for the front brakes….
 

mleach72

Well-Known Member
When I took it apart I seen that screw and wondered what it was for. It didn’t seem to go to anything lol. I got it all put back together and it works great. The spring wasn’t broke. The piston was just super tight in the bore and wouldn’t move easily. I did break the reed switch putting it back together though. I’m assuming I’ll need to buy the new board with the buttons. So now my brakes work awesome but no brake light for the front brakes….
Get a hold of Eric at bigdogpartskingpin.com or Curtis at wildsteedworx.com. You may be able to buy just the reed switch. You will have to let them know if you have the soldered style or the plug in style.
 

SBMike

Member
Get a hold of Eric at bigdogpartskingpin.com or Curtis at wildsteedworx.com. You may be able to buy just the reed switch. You will have to let them know if you have the soldered style or the plug in style.
It’s the soldered one.
 

Mr. Wright

Knows some things
Supporting Member
It’s the soldered one.
Don't try soldering it back to the board. You'll mess up the foil on the back. I've had to repair many of them that the guys have messed up. Splice the wires together and put heat shrink around it. It'll be a lot easier if you leave about 3/4 of an inch wire on the board.
 

SBMike

Member
Don't try soldering it back to the board. You'll mess up the foil on the back. I've had to repair many of them that the guys have messed up. Splice the wires together and put heat shrink around it. It'll be a lot easier if you leave about 3/4 of an inch wire on the board.
I solder pretty well and would probably tried it. But you make a excellent point and that sounds like the best way. No chance of messing up the board. Thanks
 
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