Weird brake light problem. Pampera 2-stroke

[Blambo]

Hi,

My Pamoera 250 Mk3 and I, despite our advancing years, took part in a 100 mile Long-Distance-trial.
There were a few things requiring attention after many falls in the event, including the brake light being on all the time.
The Rear brake master cylinder had taken a whack, the wires were mashed, so I guessed that was the problem.
I disconnected the wiring from the loom and started her up; brake light still on.
OK, maybe the front brake light switch also has a problem, so I pulled the wire out of the plunger switch.
STILL the brake light comes on whenever the engine runs.
So, check me out here, what am I missing.
BOTH of the switches that can trigger the brake light are disconnected and still the light is on (!!!).
Any pointers most gratefully accepted.
Mike

 

[gasgasman]

Headlight switch on?
Or the wires pinched in the loom at the rear master cylinder.

 

[Neil E.]

Some mechanical brake light switches have normally closed contacts. That means if the switch is removed from it's location, the contacts will be closed turning your brake light on. When mounted normally some part of the lever or pedal pushes on the switch to hold the contacts open.

Ignore this info if you have hydraulically actuated switches (although they can be on if the internal plunger is stuck). If you removed the wiring from your switches, then there has to be a short somewhere causing your problem. Inspect the loom carefully.

 

[slocalspode]

On my 2005 MK3 Pampera, the front switch is the normally closed type
like Neil mentions. The rear switch is the banjo bolt hydraulic type.
Neil's suggestions are spot on. If you pull the connectors from the front
switch, connect them together to prevent the brake light from activating.
Disconnect them and the light should turn on if working properly.
The opposite should apply if you are testing the rear switch.
Are you sure it is the brake light? Or could it be the running light?
Turn the headlight(s) off at the handle bar switch..
Sorry for no exact answer to your issue. Just got to chase the problem.
Jeff

Some mechanical brake light switches have normally closed contacts. That means if the switch is removed from it's location, the contacts will be closed turning your brake light on. When mounted normally some part of the lever or pedal pushes on the switch to hold the contacts open.

Ignore this info if you have hydraulically actuated switches (although they can be on if the internal plunger is stuck). If you removed the wiring from your switches, then there has to be a short somewhere causing your problem. Inspect the loom carefully.

 

[Blambo]

Brake light problem resolved in part, but a challenge remains

Hi all, many thanks for your thought which were right on the money as always. This will teach me to work without my glasses in a poorly lit garage; I should have looked more carefully, but I still need some advice with the getting round some damage, please see below...

Yup, the 'wire' I disconnected from the front brake is a plunger type switch, so out of position, the light is always on.
Progress
The bike now has a brake light that is off, until I use the front brake.
Nothing doing at the back however, the wires emerging from the switch embedded in the master cylinder are in very bad shape.
one is totally detached and one is hanging by a thread.

So, options:-
1/. Attach a 'pull-for-on' sprung switch (that I happen to have in my box of parts) to the brake pedal; the movement pulls the plunger out and makes the contact.
This will get me through the annual MOT inspection that's due at the end of the month but will be very vulnerable to knocks and mud on the trail.

2/. I'd rather repair the original switching setup.

How to connect the wires to the tiny stumps of wire that disappear into the plastic f the switch body ?
I am minded to solder very small washers to the ends of the wires that connect the switch to the wiring-loom and to screw tiny screws into the stumps of the wires in the switch, to compress these washers and hence, the wires into place and be in electrical contact via the screws..

Or, I could 'excavate' (dig/melt away) some of the plastic and try to solder the wires to the stumps of the existing wires.

The switch certainly works; if I dig the contacts of my multimeter into what's left of the exposed wires it makes the contact when I depress the lever; I just need to restore connectivity to it.

Any thoughts on this, or alternative approaches most welcome as always.

The difficulty getting parts for a 2002 GasGas does mean that some bodges and old-school first-principle approaches are required now and again
If I wanted an easy life I'd buy a KTM like all my mates, but I think my Pampera will outlast them all.

 

[cbutler]

Just buy a new pressure switch. Screw it on bleed the brakes hook the wires up and be done with it

 

[slocalspode]

Is this how your switch looks like?
This is the Banjo Bolt pressure switch on my '05 Pampera.
Like cbutler mentioned, just buy and replace the switch.
The hard part is bleeding the brake line. Can be a PIA.

 

[Blambo]

Replacing the pressure switch

Yes, that's what mne looks like too.
Looks like a Brembo logo and 4767 cast into the body.
My experience with Brembo arts fpr my BMW Dakar has been been really poor (couldn't even buy a seal kit!) but there are plenty of 'std' ones on e-bay for not much money.
Just need to get the right thread, seems there are 1mm and 1.25mm available.
Thanks to everyone; I'll be legal and riding again soon...
Mike
.

 

[Blambo]

Getting the right part, a few words that may help

For benefit of anyone who is replacing the pressure switch in their rear brake master cylinder...
Most of the ones for sale on ebay are too long.
You could turn one down in a lathe, or, look for one that says it's good for Ducati/KTM/Other European marques.
These folks use Brembo too.
You can tell from the photos that the ones for Japanese bikes re too long; the threaded part is not in proportion to the other end.
It's a std 10mm diameter with a 1mm thread.
(90% of these things are 1mm, a few are 'coarse' 1.25mm thread).
Mine cost me just over 5 UKP, delivered. This is about 6.5-7 USD.

Now for the fun of bleeding the rear brake
Mike