Date: Sun, 28 Dec 1997 17:40:08 GMT From: Ywan Mason <ymasonnopsamsouth.net> Subject: Re: Brake and ABS lights stay on???
Has the fluid been flushed? This is normal maintainence on the car every 30K or once a year. A lot of times it will take care of the problem. Proper procedures must be followed to get the valve body and entire circuit flushed, namely first pumping the brakes with the key off until the pedal becomes noticeably harder, relieving accumulator pressure and the emptying as much of the reservoir as possible with a suction gun and then refilling with fresh DOT 4 fluid. Then open a bleeder screw and slightly depressing the brake pedal, holding it depressed. An assistant or appropriate stick will do this. Then turn the key on and pressure bleeding the system. Close the bleeder, wait for the light to go out, and turn off the key. Again pump the pedal with the key off to depressurize the system and go to the next bleeder and repeat the procedure until all wheels flow clear, clean fluid. Allow time between wheels for the pump to cool down as it runs to flush the valve body and those circuits. It takes up to 2 L of fluid to get a clean system if the original fluid is really dirty. Start at the farthest caliper from the reservoir which on a 9000 because of line routing is the left rear wheel. In an older car, the first start taking longer to get the lights out indicates that the pressure in the system is dropping and the pump has to work longer to resupply it. Possible problems besides dirty fluid are the accumulator or the pressure switch. But as long as the light goes out and the ABS functions, I'd flush it and wait until it showed more major symptoms. The training manual lists up to 20-30 secs as a normal delay in the lights extinguishing for the first start of the day. Ywan Mason