Brake Light and Chime (ding-ding-ding)

I just went outside and checked the brake fluid reservoir. I'm happy to report it's full.

I did notice a wire/plug attached to the reservoir. It looks older than the others but don't think it's decrepid. I unplugged it and plugged it back in. Weirdly, the plug does not snap/clip into place even though the piece it still attached. Is this it? I may be coming loose setting off the light?

That's very strange. It could indeed be the sensor plug, but that doesn't explain the chime coming on only when you accelerate. That behavior indicates the fluid is actually low. Is it possible anyone else might have filled the fluid without you knowing?

Does the warning lamp/chime still set when you drive the car? Try engaging and then releasing the parking brake to ensure it works.

AA wrote:

Try engaging and then releasing the parking brake to ensure it works.

That was the first thing I did when I saw it for the first time. Having had work done, I wasn't sure if they applied the e-brake. I know my old Riv had a weird e-brake that didn't seem to 'set', yet it was never an issue when I got it inspected every year.

So when I saw this light, I pulled over, set the e-brake (the light stayed on), then I disengaged it and the light went out. I proceeded to move without the issue but as soon as I got onto a main road and accelerated a bit it came back one.


P.S. my girlfriend could have gotten her new 2012 Ford Fusion for $15,887 after incentives today but decided waiting a month to buy the same car for $24k. Seriously this casual attitude towards money could be an issue when we go off into the world together. Sometimes I joke she is my Operah and I am her Steadman.

I checked wrong.


When I went out to see if the brake fluid reservoir was still full I noticed, based on the size of the reservoir, that it looked like it had the majority of fluid inside the container. There was no noticeable fill line so I figured it was enough.

I pulled into my mechanic's service center and the inspection sticker guy shakes his head like 'not again'. We really do seem to bring in all the winners, whether it be my Riv, the AirBag code on the Miata or my dad aweful truck.

I taked to my mechanic, he told me to pull the car to the garage door, went to his workbench to retrieve the bottle of brake fluid, and filled the reservoir to the top. Fixed.

He pointed out the issue, it was the "master" that was leaking. Master cylinder? It's right behind the reservoir and in front of the steering wheel.

My $0.02: Consider replacing the MC and reservoir. my guess is based on your electrical connector not fitting that the OE setup has already been replaced once. What you might really want is a *rebuilt8 not new MC. The rebuilt one should have a electrical connector that fits right, and as well (if it is a Cardone) will have been bored out and sleeved not just honed. Basically you're looking for a rebuilt that's marked Ate or Bendix (got the mark cast into the MC metal).

The MC should *not* be leaking - even though it is a slow leak and you can top it off, the most important system on the car is the brakes. No matter what else is happening, you must be able to stop two tons of fun.

Master Cylinder to me sounds as serious as head gasket and computer. How much does these things run?

If you are losing any brake fluid it's not okay. You should not have to add brake fluid. I would wait until you need to add it again just to be sure. keep an eye on the fluid level.

Andysdorm wrote:

Master Cylinder to me sounds as serious as head gasket and computer. How much does these things run?

They aren't that expensive but do require you to bleed the master cylinder and then all of the brakes afterward.

Sometimes the master cylinder can leak fluid internally into the brake booster. But - make sure there is no external leak from the lines or other components. Having had the lines redone, they are suspect. At least worth having the shop do a check. The master cylinder on our cars is a quality unit. Many are still original after 10 years and 100k miles.

If there's absolutely no leaking from the lines, hoses, or calipers, have the master cylinder replaced. It's a ~$75 part + approx 2 hours labor, I'd guess. Or you can save $200 and do the job yourself.