Flashing dash brake light

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blackbirdxx
Posts: 66
Joined: Wed Mar 13, 2013 1:39 pm
Location: London UK

Flashing dash brake light

Post by blackbirdxx »

Hi,
I have just finished refurbishing the instrument cluster unit on my 1987 E24. Everything is back in the car and everything works apart from one thing. The red dash brake light which only goes off when you press the brake pedal flashes continually. If you pump the brakes a couple of times it will go off for a couple of seconds but will then continue to flash.
Has anybody experienced this problem and is it likely to be a circuit board problem or something else? I’m hoping that the electrics will settle down in time, what do you guys think.

Thanking you in advance.
Chris Wright

Post by Chris Wright »

Just to be sure, which light are you talking about? I don't know of a light in the cluster that goes off when you press the brakes except the Yellow "Check" light in the cluster that warns that something is on in the check panel?

I'm assuming you are talking about the red Brake Warning light in the cluster, not the red Brake Lining warning light next to it, or the brake stop light warning in the check panel to the left of the cluster?


The Brake Warning light in the cluster has three different switches that will set it off and I think two of them go through a flasher in the cluster (See Pg 6210-3 of the ETM), but this is the first time I have heard of anyone's flasher working!? :shock:

The switches are:
1) Brake fluid level: located on the brake reservoir cap. Closes when low.
It goes through a transistor straight to the warning light and I believe it would burn steady.

2) Brake accumulator pressure: Located on the top of the regulator. Closes below 22bar (319psi). Warns of low brake bomb pressure

3) Hydraulic system pressure: Located on the side of the regulator. Closes below 1.5bar (22psi). Warns of a catastrophic hydraulic system failure, like a burst hose or broken pump belt.

Both of these seem to be shown wired through a flasher in the cluster.

Check the two pressure switches on the regulator by unplugging them one at a time and seeing when the light goes out. They are known to fail internally and leak fluid out around the prongs for the plugs.

They used to be around $25 at the usual suspects like AutoHaus.
blackbirdxx
Posts: 66
Joined: Wed Mar 13, 2013 1:39 pm
Location: London UK

Post by blackbirdxx »

Hi,
Just to confirm, its the warning light immediately to the left of the parking brake warning light (hand brake light) beneath the rev counter.
thanks
AusE24

Post by AusE24 »

Often it is a failed brake accumulator. If the brake pedal is initially hard, then slowly sinks to the normal brake pedal height, it will be an accumulator.

regards

Greg
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