Break warning light come on and off on dash

[bruce0610]

Break warning light has started to flash up on my dash. Sometimes it stays on and sometimes it's intermittent. Checked the handbrake, light come on when handbrake is applied and goes off like normal when it should. Check brake fluid reservoir. Made sure it was topped up to max level line. When the break light came on I took off the break fluid sensor(break light warning went off) and then put the sensor clip back on(break warning light can come back on). Could this just be a dodgy break fluid sensor?

Something else I have done recently. Car sat for a few weeks and wheels were seized. Managed to break them off while driving. I thought I could hear the handbrake still stuck on a little from the back wheels. Took a bit of wood against the back wheels and hit it with a hammer to loosen any potential rust

 

[RUM4MO]

It could be a brake fluid level sensor that has gone faulty, not a typical fault I’d think, but you might just be unlucky.

One thing to try is, find something like a paper clip and short the cable wires together by fitting that paper clip into the connector socket pins. If the light is on with the paper clip in place and off with the paper clip removed, then I’d think that you have found the faulty part.

 

[bruce0610]

Thanks for the reply.

Is this a tricky thing to replace?

 

[RUM4MO]

I’d think that the sensor will be built into the reservoir on your car, I’m guessing that the connector plugs into the reservoir and not the reservoir cap.

What is the age of your car?

 

[bruce0610]

I’d think that the sensor will be built into the reservoir on your car, I’m guessing that the connector plugs into the reservoir and not the reservoir cap.

What is the age of your car?

Yes the connector plugs into the reservoir itself. It's 2011

 

[RUM4MO]

That was what I expected even although the official parts listing diagrams shows the sensor is part of the cap - just goes to prove that all these official diagrams, while defining the correct part numbers, do not always show the correct and latest detail, I also checked the same early 9R Polo and 6C Polo diagrams and again both showed the sensor built into the cap and not the reservoir - but I know that my wife's August 2015 6C Polo 1.2TSI 110PS does have the fluid level sensor built into the reservoir and not as shown in that parts listing!
So, it will be a replacement reservoir that your car needs if it turns out after checking/testing as I suggested, that that is what you find out.

Edit:- if I was doing that job, I'd get hold of an old turkey baster and remove as much fluid was possible out of that reservoir to minimise spillage when you remove the reservoir from the mater cylinder. I've removed the reservoir from a Polo master cylinder and it came away quite easily - I had bought a used mater cylinder complete with Hall sensor assembly and reservoir and cap - I needed some of these parts to make up a test rig for my Gunson's pressure bleeders! And, I sealed up the vent in the cap diaphragm so that I can it to seal up the brake reservoirs in our cars while I'm opening up the hydraulics.
You want to consider buying new seals, 2 of them to fit to the next reservoir to avoid ending up with a leaking system.