Front brake light switch

[Guest]

I ordered a new master cylinder, as well as a hydraulic switch (10x1.00). However, it doesn't fit in the hole on the master cylinder.
It has those two prongs on it, which isn't directly compatible with the stock brake light contact that went with the original MC. Since I'm forced to use the bolt that came with it, what should I do so my rear brake light works?

 

[Steve]

OK, are we discussing the front or rear brake?

The title of the thread is "Front brake light switch". You then mention getting a new master cylinder (did not specify front or rear, so since the title is front, we are assuming front) and a hydraulic switch.

You then ask what you should do to make sure your rear brake works.

.

 

[Guest]

If this is an issue with the front brake of a 1980 GS550E I'd recommend ordering Suzuki part number 57460-09300. Otherwise you can purchase another hydraulic switch, but it takes a different pitch. I can't recall but I think it was 1.25. I believe the cleanest looking install is with the oe switch in the part number provided.

 

[Guest]

Wait a second, is it some Ebay aftermarket cylinder? Your best bet may just be finding a switch bolt in the right pitch. If I remember correctly most Japanese bikes use 1.25 pitch.

 

[Steve]

1.25 pitch was for normal stuff, brakes were 1.0.

.

 

[Guest]

OK, are we discussing the front or rear brake?

The title of the thread is "Front brake light switch". You then mention getting a new master cylinder (did not specify front or rear, so since the title is front, we are assuming front) and a hydraulic switch.

You then ask what you should do to make sure your rear brake works.

.

"Rear brake light" is what I said, though come to think of it, that's something of a... I don't remember the word for it, but it's basically saying the same thing twice. Yes, the front brake master cylinder. The original one that came off was 1.00, not 1.25. I ordered a 1.00 hydraulic switch and it fit perfectly. Then I ordered a master cylinder, but the bolt hole is smaller than the hydraulic switch bolt.

 

[Guest]

Wait a second, is it some Ebay aftermarket cylinder? Your best bet may just be finding a switch bolt in the right pitch. If I remember correctly most Japanese bikes use 1.25 pitch.

Yes it is. And mine has a 1.00 pitch. The pitch is simply the angle of the worm, correct?

 

[Rich82GS750TZ]

brakelight activating banjo bolts can be had in either 10x1.00 or 10x1.25. here's a 1.25 from revzilla.
https://www.revzilla.com/motorcycle...VCIzICh1mxQU-EAQYAiABEgIOs_D_BwE&gclsrc=aw.ds

 

[Guest]

Here's a comparison. The dark bolt came with the new front brake master cylinder. The light bolt is the hydraulic switch.

 

[Steve]

... Then I ordered a master cylinder, but the bolt hole is smaller than the hydraulic switch bolt.

Is the new master cylinder a Suzuki part or aftermarket? Even aftermarket parts <made for> Suzukis tend to keep stock bolt specs.

Yes it is. And mine has a 1.00 pitch. The pitch is simply the angle of the worm, correct?

You have the right idea, but very specifically, the "pitch" is the distance from the top of one thread to the next. In this case, the stock pitch of 1.0 would mean that the tops of the threads are 1.0 mm apart. That is a finer pitch than the other bolt, which appears to be a 1.25. If you have calipers, measure the distance covered by four threads. It should read 4.0 or 5.0 mm. If we are totally wrong and it's a wider 1.5 pitch, that distance will be 6.0 mm.

American (SAE) hardware uses the number of threads per inch. Metric hardware measures from peak to peak on the threads.

.

 

[Guest]

brakelight activating banjo bolts can be had in either 10x1.00 or 10x1.25. here's a 1.25 from revzilla.
https://www.revzilla.com/motorcycle...VCIzICh1mxQU-EAQYAiABEgIOs_D_BwE&gclsrc=aw.ds

I got those for my bike. Rear brake one works fine, front one didn't, replaced it back to stock unit. You need a lot of pressure on these to activate. The rear gets plenty because of the leg and foot, the front is lacking the same force as the rear. You have to really bear down on the front brake lever for it to work and that can be a problem.

 

[salty_monk]

Doesn't your new mastercylinder have it's own switch? If not I suggest you track down a take off unit from something like a KLR 650, Ninja 250 etc. Something with a single brake. Make sure to get one with Mirror mount if you are using it. You can put two spade connectors on the microswitch that comes with more modern equipment. Either crimp those to the wires from you original GS master cylinder or make up a new wire with Spade terminals one end & bullets the other to work with the GS loom... it's not rocket science....

 

[Guest]

Spade and bullet connectors don't fit together. And I know, I can just cut off that original end off the wire, and put connectors on it. I'd just like to refrain from butchering it further, if I can. But if I must, then I must.

 

[salty_monk]

You need Bullets on one end to go into the stock harness & spades to go to the new master cylinder microswitch... I'm talking about opposite ends of the same wire.

 

[Guest]

You need Bullets on one end to go into the stock harness & spades to go to the new master cylinder microswitch... I'm talking about opposite ends of the same wire.

Remember, autism lol.
So the wire that has a plastic plate on the end (that connected to the original switch), I should remove that entirely and replace it with a new wire? Why not cut the end off the existing wire, put spade connectors on it, and hook it up to the hydraulic switch?

 

[Guest]

It's normally wise to use minimal effort to maximum effect, so I would do exactly as you suggest. Use the existing wiring, and modify the terminals to fit the new switch.

 

[Guest]

It's normally wise to use minimal effort to maximum effect, so I would do exactly as you suggest. Use the existing wiring, and modify the terminals to fit the new switch.

There's an orange wire and what appears to be a black wire (I only took a quick glance, I'll go back out when it gets above 35 degrees). However, the prongs on the front master cylinder aren't labeled. Are they specific to positive or negative, or can either wire go to either prong?

 

[Guest]

Electrical items aren't my strong suit. I think you'd be ok either way, but I'd suggest try one way - if it doesn't work, try the other. You can't hurt anything if you pick the wrong way round first time.

 

[Steve]

There is no polarity on the brake switch, the wires can be connected either way. :encouragement:

.

 

[Guest]

Electrical items aren't my strong suit. I think you'd be ok either way, but I'd suggest try one way - if it doesn't work, try the other. You can't hurt anything if you pick the wrong way round first time.

You and I have the exact same bike. Mine was made 11/79.