Magura brake pressure switch

[trazor]

Nice find.

If I understand correctly, this inserts between the hose and the actual handle bar unit, becoming a part of the hose? Pls report your experience if you get a pair. (I'm looking for something that might fit Hayes Nine brakes.)

Yep you need to cut your hydaulic hose with a sharp knife. Insert the pressure switches and wire them up, bleed the system. They work very well.
Very pleased with them.

7 years after the initial post, how these switches are going? I just brought the last one on Amazon US but not tested yet. Checki for online availability and the Magura homepage, looks like these are discontinued. They have the "e" versions of their complete brake systems. Still, I think this kind of generic hydraulic switch is a good idea. Somebody knows if this kind of switch is provided by other manufacturers?

 

[knutselmaaster]

These still exist. There are 2 versions; one that opens on pressure and one that closes on pressure, so be sure to take the right version or else you will have to brake to get the motor to run :wink:

 

[Kirill]

I bought this sensor Magura Pressure Switch / Cut Off for E-Bike, for all Rim and MT Disc Brakes up to MY2014 - 0724344.

Pretty strange works. The sensor is too sensitive or defective. Even after several hours inaction, the circuit is closed. Needs to sharply press the brake lever several times to open the circuit. There is no question of any clear work. I push the handle a little a few millimeters and the circuit closes. But immediately after installation, the response was better.

The brakes work great. There is a handle stroke. You can adjust the severity of braking.

What is the problem?

 

[knutselmaaster]

It could be a short circuit in the wiring.
Is the brake fluid clean?
Too much brake fluid in the circuit, pressure doesn't go back to "0"?

 

[Kirill]

There is no short circuit.
Тhe brake fluid is as clean as possible. New from the bottle.
The brakes are working normally. Pressure is generated by the handle. Pistons return back properly.

 

[knutselmaaster]

Is it mineral oil? They don't work well with DOT

 

[trazor]

I bought this sensor Magura Pressure Switch / Cut Off for E-Bike, for all Rim and MT Disc Brakes up to MY2014 - 0724344.

Pretty strange works. The sensor is too sensitive or defective. Even after several hours inaction, the circuit is closed. Needs to sharply press the brake lever several times to open the circuit. There is no question of any clear work. I push the handle a little a few millimeters and the circuit closes. But immediately after installation, the response was better.

The brakes work great. There is a handle stroke. You can adjust the severity of braking.

What is the problem?

I've installed three of these on different brakes (shimano deore/zee, magura mt5) and never saw a problem like that (or any problem). Looks like a defective unit to me, probably the pressure actuator is stuck. Which brake/model brand are you using?

 

[Kirill]

Is it mineral oil? They don't work well with DOT

DOT 5.1

 

[Kirill]

Which brake/model brand are you using?

Hope Tech 3

 

[knutselmaaster]

The sensors are mineral only, as all Magura brakes use mineral.
You could try to clean out all DOT fluid (very thoroughly) and replace it with mineral, it will make the brakes feel a bit less nice but not much and it shouldn't be of any harm.
We've done so on a client's bike with Avid brakes and it works quite well.

 

[Kirill]

The sensors are mineral only, as all Magura brakes use mineral.
You could try to clean out all DOT fluid (very thoroughly) and replace it with mineral, it will make the brakes feel a bit less nice but not much and it shouldn't be of any harm.
We've done so on a client's bike with Avid brakes and it works quite well.

How can the type of oil affect work?

 

[amberwolf]

Different fluids may affect plastics and seals within the devices differently. If the DOT fluid has something in it that is a solvent for one of the plastics or gaskets inside the switch, these could have swollen up and caused the switch to begin sticking.

If that's the case, the switch is damaged and probably needs to be replaced.


There are ways to add a magnetic or physical switch to the lever itself, or to the caliper, that will engage an ebrake signal, if you can't use the pressure type.

 

[Kirill]

Different fluids may affect plastics and seals within the devices differently. If the DOT fluid has something in it that is a solvent for one of the plastics or gaskets inside the switch, these could have swollen up and caused the switch to begin sticking.

If that's the case, the switch is damaged and probably needs to be replaced.


There are ways to add a magnetic or physical switch to the lever itself, or to the caliper, that will engage an ebrake signal, if you can't use the pressure type.

I know that DOT is aggressive liquid but I figured this was the case with the surrounding parts, the paintwork, the plastic and rubber parts, and the inside was made from resistant materials.

I wanted something more reliable than lever sensors.

 

[Kirill]

The Magura’s sensor started works.
I didn’t remove the sensor from the hydraulic line.
Because in this case I would have to somehow connect the hydraulic line.
For almost three years I used a limit switch for brake signal instead of a Magura's sensor. But all methods with switches are unreliable and complete crap.

All this time I was very upset that the sensor didn’t work after installation. I had bleed the system a couple of times. And I used the original Hope fluid.

I didn't lose а hope. Of course, having a set of brakes from the Hope brand.
But I didn't try to check every day. I accidentally picked up a multimeter and checked for a short circuit. It works! I connected two wires from the brake light to see it with my own eyes.

I felt offended for the time spent on installation and money spent on a useless thing.
But now I’m happy!!!

 

[aae34]

i guess i should put mine into use already. i'm not sure, but this topic was possibly
one of the reasons i haven't gotten around to actually using that sensor.

 

[Kirill]

I don't know why started works. Perhaps after several years of use the liquid has become less aggressive. Or the internal part responsible for measuring pressure has come to terms with this environment)))
But now I'm afraid even to bleed the brakes.

 

[Kirill]

i guess i should put mine into use already. i'm not sure, but this topic was possibly
one of the reasons i haven't gotten around to actually using that sensor.

In general, first needs to understand how aggressive DOT 4 and DOT 5.1 are in terms of composition.
For example, Hope allows to use not only 5.1 but also DOT 4