I start the engine, but the brake indicator light stays on (and NO, my emergency brake is not applied)! I had a mechanical fitness certification done about 3 months ago, and brake pads were almost like new.

Is this the red "BRAKE" light (parking brake or low fluid) or the brake wear indicator? If it is the red "BRAKE" light check your brake fluid level.

Check to make sure that there is not any slop in the parking brake pedal, if you make sure it is all the way up (with hand or foot) I am betting the light will go out. If its still on even with the pedal all the way up and your sure the little switch under there for it is not triggered, then I would check my brake fluid level in the resevoir, as there's two level switches in there that will also trigger that light.

__________________
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You have 2 brake indicator lights.

1. a RED brake light. This is to indicate 2 items. First the the parking brake is on. If it is off check the switch located at the top of the parking brake pedal assembly. And second that the brake master cylinder reservoir is low. there are 2 chambers int he reservoir. Each one has a switch in it. Check the fluid level and then the switches.

2. You have a brake wear indicator. It is the yellowish white light with the 2 round circles. One, the inner one, solid and the outer one segmented. This is the wear indicator. If this is on then one of the "contact" sensors is probably exposed or bad assuming that the pads are OK. It could also be one of the wires that leads to the caliper.

Dave

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__________________
1970 220D, owned 1980-1990
1980 240D, owned 1990-1992
1982 300TD, owned 1992-1993
1986 300SDL, owned 1993-2004
1999 E300, owned 1999-2003
1982 300TD, 213,880mi, owned since Nov 18, 1991- Aug 4, 2010 SOLD
1988 560SL, 100,000mi, owned since 1995
1965 Mustang Fastback Mileage Unknown(My sons)
1983 240D, 176,000mi (My daughers) owned since 2004
2007 Honda Accord EX-L I4 auto, the new daily driver
1985 300D 264,000mi Son's new daily driver.(sold)
2008 Hyundai Tiberon. Daughters new car

If all else fails, I have seen the float go bad, sink in the brake fluid and activate the light.

My thanks to Craig; pawoSD; dmorrison ; and silverstar-1984 for the prompt replies and suggested causes of the problem.

It is the Red Brake Indicator indicator light to which I referred. I had surmised that it might be a low fluid level, but topping it up didn't eliminate the problem.
The brake release mechanism seems to be fully released, I will investigate the other suggestions in due course, i.e., float switches, Brake pedal switch, etc.

Thanks again gentlemen for your replies, which are indeed appreciated.

I have the same problem on my '77 300D (the red brake light stays on). The brake system itself is fine - however my "power" brakes really don't work. I attribute this to either a failing master cylinder or possibly the vaccum pump. Considering my power door locks don't work either, it's most likely a failing vacuum pump.

If you have to push hard on the brake pedal to stop the car, it may be one of the above. Otherwise I don't think it's a big deal if the light is on.

I have this same problem, the rear float got a wild hair up its rear and decided to sink last week.

Mine only comes on when I go around a right hand corner