FXR Master Cylinder
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FXR Master Cylinder
Hi All,
I'm replacing a master cylinder on my '85 fxr and have run into a little issue. On my old master cyclinder, there was a pressure switch which screwed into the side of the cylinder and activated the brake lights. Well, the shiny new master sylinder doesn't have the threaded hole on the side for the pressure switch, so...
How do I activate my brake lights? Is there an "in-line" pressure switch of some kind for a FXR master cylinder? (On the caliper line?) Can it be triggered mechanically somewhere else? Any input on how YOUR system works would be greatly appreciated.
GM
I'm replacing a master cylinder on my '85 fxr and have run into a little issue. On my old master cyclinder, there was a pressure switch which screwed into the side of the cylinder and activated the brake lights. Well, the shiny new master sylinder doesn't have the threaded hole on the side for the pressure switch, so...
How do I activate my brake lights? Is there an "in-line" pressure switch of some kind for a FXR master cylinder? (On the caliper line?) Can it be triggered mechanically somewhere else? Any input on how YOUR system works would be greatly appreciated.
GM
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RE: FXR Master Cylinder
I looked at mine at lunch time, and it doesn't have a pressure switch anywhere along the line('89 FXRS-SP with dual front calipers). When I squeeze the front brake lever, I can hear a relay clicking in the headlight, so I'm assuming some kind of electronic switch on the lever itself.
My rear brake is a pressure switch, but isn't working very well, any idea how to adjust the sensitivity? You have to really stand on the brake pedal to get it to light.
My rear brake is a pressure switch, but isn't working very well, any idea how to adjust the sensitivity? You have to really stand on the brake pedal to get it to light.
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From: Bellville, Tx
RE: FXR Master Cylinder
I had rear brakepressure switchmounted sticking up and foundthat an air bubble would form there and it wouldn't bleed out. I repositioned it so it hung down and it works fine now. Hope that helps.
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RE: FXR Master Cylinder
Yeah, I guess I forgot to mention that it's a rear master cylinder that I'm working with. I had similar issue that you did with having to stand on the brake pedal to get the tail light to work. I just replaced the pressure switch and it worked fine. The air bubble sounds feasible, wish I had thought of that before I replaced the last switch.
In any case, is there any way to activate the tail light from the rear brake WITHOUT that pressure switch? Never much liked it anyway and the new master cylinder I've got doesn't have the port for that pressure switch anyway.
GM
In any case, is there any way to activate the tail light from the rear brake WITHOUT that pressure switch? Never much liked it anyway and the new master cylinder I've got doesn't have the port for that pressure switch anyway.
GM
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From: Bellville, Tx
RE: FXR Master Cylinder
Yes, the original brake switch on knuck and pan was a pull switch(looked like a little can with a rod sticking out) it attached to the brake peddle thru a spring and activated when the brake pedal was depressed. Most catalogs will have it in the classic sections. Maybe someone into the older bikes can give you a source. It can be done.
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RE: FXR Master Cylinder
Duh, too many years of riding bikes with rear drums, I always forget that there are two master cylinders. My pressure switch is in the brake line, not the master cylinder itself, so one option would be to get that switch. The Clymer manual says that both were used during that era.
I'll have to try rotating mine. I always use both brakes so it's only a problem once a year at state inspection time.
I'll have to try rotating mine. I always use both brakes so it's only a problem once a year at state inspection time.
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RE: FXR Master Cylinder
Thanks uesque, I was hoping someone would tell me that. I'll look into that one. And thanks to DeJavu, I'll look into that as well, as I've always had intermittent problems with those pressure switches and feel a simple mechanical solution would be a bit better. While I generally use both brakes to stop, there have been times when one or the other didn't work (dropped a brake pad after my LAST visit to the Harley shop for some work!). Since I live in touristland (Florida) brake lights are pretty important, though they still tend to be ignored. Many thanks for everyone's help, you guys ROCK!
GM
GM
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Road Warrior
Joined: Nov 2006
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From: Deltona, FL
RE: FXR Master Cylinder
I actually replaced my rear master cylinder with one that was incorporated into my forward controls. What I did was to take a brake line junction block that had a 90 degree bracket hanging off of it. Basically, this was a little cylinder with threaded connections on both ends for standard brake line connections and then a threaded hole in the middle. Thread a pressure switch into the hole and then hang it off one of the tranny bolts. Then you just need to get your brake line to fit.
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