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Registered
Join Date: Dec 2000
Location: uk
Posts: 32
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Brake warning light on - 1980 SC
I have never had the brake warning light staying on after starting the car up but just the other day, it came on and stayed on. Checked the reservoir and the connections into that....any ideas?
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08-21-2001, 02:29 AM
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Registered
Join Date: Feb 2001
Location: Aachen, Germany
Posts: 43
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On my 1980 SC ROW model, the brake warning light, once engaged by something unusual like a brake pad contact, will stay on until you disconnect the battery for a moment. I have drawn a wiring schematic of the early warning light assembly (with 2 lamps in it) where you can see why it stays on.
------------------ Robert / 80 Targa |
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08-21-2001, 04:41 AM
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Join Date: Jul 2001
Location: Shoreline,WA,USA
Posts: 30
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I am in the process of troubleshooting the same problem. My brake light comes on, disconnect battery and it goes of. It will come on again in a little while. I don't think it has anything to do with the parking brake because the light will fliker a little whien you pull the parking break on. I have discinnected both connectors on the master cylinder and the light has not come on yet. I am thinking I may have a bad sensor on the master cylinder. Next steo will be to connect one at a time. Be interested in any other experiences.
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08-21-2001, 05:39 AM
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Registered
Join Date: Dec 2000
Location: uk
Posts: 32
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The battery thing rings a bell. I hadnt used the car for a week and the battery was flat. I charged it and then the brake light was on. I will disconnect the battery and see if it cures it. Any more ideas?
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08-21-2001, 10:32 AM
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Registered
Join Date: Dec 1999
Location: TX USA
Posts: 9,804
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One or both of the switches on the master cylinder is probably sticking and causing the warning circuit to trigger. Both switches have to operate in unison, or the warning goes off. You should check each switch separately with a multimeter with engine on and have an assistant apply brake pedal pressure.
There is also the possibility of a failing master cylinder circuit ... generally the one nearest the brake booster. Check with all four wheels up, vehicle on jack stands ... engine running, you should NOT be able to turn a wheel by hand if full brake pressure is being supplied by master cylinder! The whole purpose of that warning lamp is to tell you when there is a failure, and the brakes need attention! If one of the switches is bad, it means there is too much moisture in the brake fluid and 100% should be drained and blown out with compressed air, calipers removed and drained! Switches don't stick without corrosion caused by miosture! Other parts of the system probably have damage, too! ------------------ Warren Hall 1973 911S Targa 1992 Dodge Dakota 5.2 4X4 parts hauler [This message has been edited by Early_S_Man (edited 08-21-2001).] |
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08-21-2001, 10:49 AM
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