Well, as you know that when the brake fluid gets low, light comes on. This does not happen in my Jeep ... what should I do to fix this?

 

First, I would suggest you fix the leak in your brake system.

Second, What year is your Jeep? Did it come equipped with the sensor in the reservoir? If so, you could probably fix it by replacing the sensor.

If it didn't come equipped with it and you can't live another day with out it:
Later model WJ master cylinder/booster/reservoir assemblys have this sensor in them. I'm not 100% sure how the sensor works but it should easily be adaptable to any vehicle. It would require you install the WJ brake parts. Trace the WJ wiring diagram and graft it into your Jeep.

 

many thanks! mine is a 2001 sport, there is a socket and cable for electricity under the master cylinder booster

 

Maybe the lamp behind the dash indicator is blown out.

 

No, brother, it works when I pull the hand brake ...

 

Wouldn't that be a different indicator light from the handbrake?

 

The reservoir has to be pretty much empty for the light to come on so maybe you just havent been low enough?

 

No.