I’m looking for technical help or recommendations on: park brake/brake warning light staying on…
Hi guys
The car failed its mot as the ns brake wasn’t functioning properly and there was a braking imbalance across the rear axle.
So I replaced the NS rear caliper and have bled the caliper. Adjusted the handbrake and everything is much better etc but now the warning light on the dash wont go off.
The fluid reservoir is full.
Today I disconnected the handbrake cables to both calipers and loosened the tension at the handbrake as I thought maybe something was sticking/tight and that’s why the light won’t go off, but even with everything disconnected the light won’t go off.
The handbrake is also going down as far as it will go.
I know there is a switch on the handbrake, and am wondering it it could be that?
It may be a coincidence but prior to doing the work for replacing the caliper the light wasn’t coming on unless I had the handbrake on.
It’s so frustrating as the handbrake/brakes are now operating so much better but I’m assuming if I put it in for a re-test it will fail on the warning light?
Any suggestions gratefully received…
I’m wondering if it’s because I only bled the caliper that was replaced?
Could it cause some sort of imbalance between the calipers?
If so, do you think bleeding the os rear caliper might fix it?
The warning light works off a simple, spring loaded switch at the handbrake lever. It’s not actually connected to the brake hydraulic system!
It needs to be set that when the handbrake lever is lifted one notch the switch “nose”, or plunger, pops up under the influence of its spring and closes the contacts, putting the warning light on. The switch might have been knocked out of alignment or stuck.
Hi Paul
I’ve read lots online where the light staying on has been due to the reservoir being low, so doesn’t that mean that it’s connected to the hydraulic system as well?
Tonight I removed the handbrake lever and checked the operation of the switch there and it is seated properly and the contact is opening and closing as expected. That doesn’t rule out a faulty switch I suppose.
I don’t know on these particular cars, but it is very common for there to be a float switch in the master cylinder to warn of low brake fluid.
yes its checking the level of the fluid, but not part of the pressurised hydraulic system
So I got a multimeter and checked a few things.
First of all, the mechanical swith that screws onto the handbrake lever is working OK and the contacts open and close when the lever is pulled and released.
If I remove the black connector from the switch on the lever, the light stays on.
If I stick the multimeter in the connector and touch the chassis with the other connector it bleeps.
It looks like the power to the black connector is continuous and activating the switch on the lever doesn’t break that.
Not sure what to check next?
Hi Robbie _ I have just developed a similar problem. Just had all pads and discs changed on my 2005 NC and now the light is coming on intermittently (but regularly) whilst driving. It goes off when I take handbrake off to start driving but then on and off whilst driving. This of course never happened before brakes changed. If I touch the brakes whilst driving the light goes off for a while…is the float an easy/obvious thing to see/release? Any help, thanks. Graham
This might just be caused by a slightly low brake fluid level. Natural movement when driving causes the float to move about and if the level is on the lower limit it can be just enough to put the light on and then off again.
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