Rear Brake Light Switch

[Sparky84]

Does the rear brake light switch have a lock nut on the switch body?

If not, would it be ok to put a blob of sillycone (not too much) on it to stop it from moving? Or anything else?
You adjust It, then after a short ride it seems to be moving to be on all the time again.

Cheers Alan

[Charlie-brm]

Yes, it's built like a fat and CHEAP ball point pen. Real junky. I just tore one completely down last week for a fellow FJ'er. I did my own 3 years ago and it hasn't given me any problems since. About 8 pieces in all, plus the housing. There is no lock nut, just the one plastic hex nut. If you could scavenge a nut with that thread, good luck to you.

All that said, if the switch is really touchy, I'd recommend removing it completely to a clean work table and breaking it down. Prepare not to launch any little bits since the plunger spring is always under compression. You're likely to find that the contact leafs and the contact ring that shorts them together are badly oxidized. Buff them back to bright metal, stretch the spring about 1/8" (3mm) to improve having the light go OFF when it's supposed to. Reassemble with some dielectric grease on the contact faces. That rebuild gives the switch more definitive states of ON and OFF so the little amount of switch wiggle is not a factor.

I could do a Grade 3 quality diagram if desired.

[Sparky84]

I could do a Grade 3 quality diagram if desired.

Charlie-brm Please No Grade 3 diagram required, that may mean I'll have to pass Grade 2 to understand it, but if you have the urge to be artistic and just want to get it out here rather than on a fence, house, high voltage sub, someones car, Go for it.   


Now back to the switch housing
Sorry, I may have misled you saying 'switch', the 'switch' seems to work fine but the housing which is used to adjust the operation of the ON and OFF of the 'switch' keeps self adjusting to the point of being ON (which ain't good for the arse end of my bike).

I adjusted it and within 40k's it had gone back to being ON, so maybe just a smear of sillycone near the nut and thread will do

Cheers Alan

[ribbert]

Alan, the minute I have trouble with a brake light switch, I turf it and install one of these. They only cost $10 -$20 and I've never had trouble with them. Install and forget, never needs adjusting.




Banjo hydraulic brake light switch.

Noel

[Charlie-brm]

Hey! I'm liking the hydraulic sensor alternative. That would mean any free play on the switch would depend on the actual brake lever to master cylinder settings, not any slop like in a mechanical plunger switch. Dirt free too.

I notice that RPM's switch has two hex nuts on the housing so that could be a good replacement source at a great price. http://rpmracingca.com/proddetail.asp?prod=M%2FC%3ARBLS&cat=23
I just like to tinker with fiddly stuff instead and it's handy when this stuff becomes an issue at the last minute.

This is a representation of what's going on in the plunger switch. Bottom line, if that spring loses recovery strength, when you let off the brake lever, the center metallic collar on the plunger is going to stay somewhere in contact with the two brass leafs, instead of being pushed up so the leafs are touching the lower plastic collar, ie. open circuit. I mark the spring's length and stretch it to 1/8" longer for more push.

All of those internals will come out for cleaning. The brass leafs are like extra long springy spade connectors and are retained in the housing by tabs that grip into little holes. Poke them flat with a dental pick for removal. Give the brass leafs a bit of a fresh bend too to restore some contact pressure.

[Sparky84]

Noel that Hydraulic Sensor is quite smart, so I assume you would replace the Banjo bolt on rear brake line with it?

Charlie-brm, nice diagram of how the switch works. When something like that breaks down I do pull them apart to see what has failed but I usually don't try to fix them due to the plastic body parts are glued together and trying to get them apart makes them not fit to go back together.

Also you must have some patience fiddling with all those little brass leafs and springs 

Cheers Alan

[ribbert]

Noel that Hydraulic Sensor is quite smart, so I assume you would replace the Banjo bolt on rear brake line with it?

Cheers Alan

Yes.

It's a pressure switch, so simple. If your brakes are working so is your brake light.

Noel

[Charlie-brm]

In this case, there are no fasteners or glues in that entire assembly. The end loop of the exterior spring might have to be opened with needle nose pliers to free it from the hole in the plunger rod. At the other end, the rubber cap with the wiring is just a friction fit over the body. Once it is off, the plunger, compression spring, 2 plastic sleeves and metal contact collar dump out. Dental pick to push in the retention tabs of the brass leafs. Reverse to reassemble.

(But I'm still liking that solid state alternative - hydraulic sensor switch)

Charlie

Noel that Hydraulic Sensor is quite smart, so I assume you would replace the Banjo bolt on rear brake line with it?

Charlie-brm, nice diagram of how the switch works. When something like that breaks down I do pull them apart to see what has failed but I usually don't try to fix them due to the plastic body parts are glued together and trying to get them apart makes them not fit to go back together.

Also you must have some patience fiddling with all those little brass leafs and springs 

Cheers Alan

[Pat Conlon]

If you plan on installing the hydraulic switch on the back m/c you want to check the clearance with the swing arm.
The hydraulic switch pokes out further than the oem banjo bolt.

If swing arm clearance is a problem, you could always install the hydraulic switch at the caliper.

[ribbert]

If you plan on installing the hydraulic switch on the back m/c you want to check the clearance with the swing arm.
The hydraulic switch pokes out further than the oem banjo bolt.

If swing arm clearance is a problem, you could always install the hydraulic switch at the caliper.

Pat, I have one on mine and clearance isn't a problem. You can also get 90 deg switches that don't protrude as far.

Noel

[Charlie-brm]

When you tighten down the sensor threads into the master cylinder to seal the banjo bolt, do you have some control over which way the wiring's 90 degree bend points?
Charlie

Pat, I have one on mine and clearance isn't a problem. You can also get 90 deg switches that don't protrude as far.

Noel

[ribbert]

When you tighten down the sensor threads into the master cylinder to seal the banjo bolt, do you have some control over which way the wiring's 90 degree bend points?
Charlie

Pat, I have one on mine and clearance isn't a problem. You can also get 90 deg switches that don't protrude as far.

Noel

I've never used the 90 deg fittings but I would think not. I have a straight one on the FJ. You could probably get some control over angle with another washer and/or by varying the torque on the bolt.

Noel

[aviationfred]

Noel,

Do you have a link to a preferred supplier of this hydraulic brake switch?


Fred

[ribbert]

Noel,

Do you have a link to a preferred supplier of this hydraulic brake switch?


Fred

Sorry Fred, I don't. I'll have a look at my eBay history and see if I can find it, it was just a random purchase. They are such a simple device I doubt it matters though.

Noel

[racerrad8]

Fred or anyone else that would like one of these,

We do not stock the hydraulic brake light switches but we have ordered several single banjo and double banjo (For the people using the alternative front two line kit) Our supplier has several thousand in stock and we can get them next day so there is not a big lag time for shipping.

Robert - RPM