Front brake switch.

Trevor9

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How do you remove the front brake light switch from the master cylinder? I did read that someone said the was a small hole under the lead, but I cannot find one on mine (sx650sh), imported from the USA.
 
On the MC body there's a hole under where the wire enters, the plastic end of the wire lead has a tab that catches the edge in the hole, pressing in with any suitable probe releases the lead.
KIMG0386~2.JPG
 
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How do you remove the front brake light switch from the master cylinder? I did read that someone said the was a small hole under the lead, but I cannot find one on mine (sx650sh), imported from the USA.
I had a revelation the other day. I've been fighting with those OEM type leads since I got my 1981 last winter when I was trying to remove one from the old OEM MC. I thought until this Tuesday, how in the h could this be so hard. These bikes are old and have been laid on their side multiple times. The lever housing gets knocked out of round jamming the lead in and making it hard to get a new one in.

On Tuesday I was was trying to install a new switch on a master cylinder from a 2014 v star 250 . I got the MC on ebay for 22$ and it is a real nice NISSIN 12.7mm.Yes, in a perfect world, all you have to is you press up on the hole at the bottom of the hole you stick the sensor. The hole seemed to small.

The V star must have been dropped and the hole was knocked out of round. So on Wednesday I finally figured this out.
Stuck the master cylinder in the bench vise and took a big threaded bolt of the type I used to clamp heavy pine boards on a fence gate to the post cemented in to the ground. I screwed it in and pushed the aluminum out again.

Be careful and don't go to far in. I should have used a torch and heated it up first. I cracked the aluminum a bit, but thats O.K. it worked out anyway. The lead slipped right in and holds.

Cheers Patrick
 
I had a revelation the other day. I've been fighting with those OEM type leads since I got my 1981 last winter when I was trying to remove one from the old OEM MC. I thought until this Tuesday, how in the h could this be so hard. These bikes are old and have been laid on their side multiple times. The lever housing gets knocked out of round jamming the lead in and making it hard to get a new one in.

On Tuesday I was was trying to install a new switch on a master cylinder from a 2014 v star 250 . I got the MC on ebay for 22$ and it is a real nice NISSIN 12.7mm.Yes, in a perfect world, all you have to is you press up on the hole at the bottom of the hole you stick the sensor. The hole seemed to small.

The V star must have been dropped and the hole was knocked out of round. So on Wednesday I finally figured this out.
Stuck the master cylinder in the bench vise and took a big threaded bolt of the type I used to clamp heavy pine boards on a fence gate to the post cemented in to the ground. I screwed it in and pushed the aluminum out again.

Be careful and don't go to far in. I should have used a torch and heated it up first. I cracked the aluminum a bit, but thats O.K. it worked out anyway. The lead slipped right in and holds.

Cheers Patrick

Thanks for the illuminating replies.
Unfortunately no matter how hard I push into that hole the lead/cable will not budge. I think I'll have to ruin the lead/cable and replace it with a new one.
 
Thank you for the Illuminating replies.
No matter how hard I push a probe into the hole, the lead/cable will not budge. I think I will have to ruin the lead/cable and replace it with a new one.
 
There's probably a lot of corrosion in there. I know there was on one of mine. Squirt a little penetrating oil down that hole and give it a half an hr to work it's way around inside. Then start twisting the switch one direction then the other.
It'll give itself up eventually.
 
Thanks all, after some perseverance and a lot of flushing with wd40 the lead/cable finally gave up.
Now to remove the rest.
I've been looking on evil bay and see that I can buy a pair of Chinese levers for less than a m/cylinder repair kit. Am I mad by repairing the old one or not?
 
I've renovated originals but only ones that just needed a cleaning and not a rebuild kit. If a kit is needed, I think I'd rather put that money towards a different slightly smaller MC. The originals were a bit too large and a smaller unit works better, giving better brake "feel" and modulation. Originals had a 14mm bore. Find one in the 11mm to 13mm range.
 
Inside, the bore that the piston slides in. But there's usually no need to do that, they're usually stamped on the outside somewhere. If the MC on your '81 SH is original, and it sounds like it is, it would have a 14mm bore. That was the size used on all the '78 and later 650s. Does it look like this, with a semi-rectangular, angled reservoir? .....

AjGQIhR.jpg


lzutB53.jpg


Here's the 11mm one I put on my '78 and you can clearly see it's marked with an "11" .....

avObCjs.jpg


..... and the 1/2" one I put on my '83, clearly marked "1/2" .....

dvchMIP.jpg


Your original may not be marked on the side like these but rather on the bottom.
 
Thanks all, after some perseverance and a lot of flushing with wd40 the lead/cable finally gave up.
Now to remove the rest.
I've been looking on evil bay and see that I can buy a pair of Chinese levers for less than a m/cylinder repair kit. Am I mad by repairing the old one or not?
A new or used 11 mm bore (max 12 mm) Brembo or OEM Yamaha from a newer model would be my recommendation. Just make sure you get one with a brake light switch.
The thought of Chinese made brake components makes me cringe.....
 
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Both of mine are from other old Yamaha models. I chose them because they accept the original brake light switch, lever, and have the reverse thread mirror mount. Yamaha quality was a consideration as well.
 
Thanks all, after some perseverance and a lot of flushing with wd40 the lead/cable finally gave up.
Now to remove the rest.
I've been looking on evil bay and see that I can buy a pair of Chinese levers for less than a m/cylinder repair kit. Am I mad by repairing the old one or not?
the chinese $20 12.7 worked well until 500 miles later when lever spring came out.
 
Both of mine are from other old Yamaha models. I chose them because they accept the original brake light switch, lever, and have the reverse thread mirror mount. Yamaha quality was a consideration as well.
Yes, OEM Yamaha do have the LH mirror thread. But I do not believe Brembo are inferior in any way. Rather the opposite.....
 
the chinese $20 12.7 worked well until 500 miles later when lever spring came out.
The Chinese levers have arrived (very quickly). I still have another question, I bought the stainless steel banjo bolts from a UK seller, and I notice that the holes for the fluid to pass through are smaller than the Chinese or the Yamaha originals. Does this matter?
 

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The Chinese levers have arrived (very quickly). I still have another question, I bought the stainless steel banjo bolts from a UK seller, and I notice that the holes for the fluid to pass through are smaller than the Chinese or the Yamaha originals. Does this matter?
Forgot to add that there is not any size of the bore on the master cylinder.
 
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