purging brake fluid

[harry yarnell]

Lately, I have noticed the BRAKE and ABS lamps staying on for 30 or more seconds after start-up, then go out. Seems to get slowly longer for the lamps to extinguish. Well, I drained the brake reservoir, and refreshed with new DOT 3, and now the lamps go out after 3 seconds. Every time. This doesn't make any sense. The system worked perfectly before, perfectly afterwards; why changing the fluid would have any bearing on pressure buildup (assumption on my part), I don't know. The old fluid was dirty, but not nasty.

[Barney Eaton]

Possible answer... the lights are controlled from the BCM which get signals from the pressure switch. There is a fairly small port going to the pressure switch. Since the fluid movement inside this port is small, it is probably much more stagnent than the rest of the fluid. The new clean fluid probably diluted the mess enough to get a better signal from the switch. <P>When I flushed my system last week, I thought about pulling the pressure switch and cleaning it and the port between it and the pump. Turns out the special deep socket I reworked has walls that are too thick and will not clear the pump motor. Now looking for a cheap 36mm deep socket (with thin walls) to remove pressure switches.

[Guest wally888]

Harry,<BR> Not sure you mean the lights go out in 3 seconds even if car has set w/ ignition off, for some time? If so, you have a bad Pressure Sensor and it is shutting pump off too soon. And you have no lights but also little Pressure.

[Guest]

This may sound funny, but my ABS light stays on if I have not used my foot brake, but if I do it goes out in a few seconds. The regular brake light seems to have a mind of its own: usually going out after a few seconds but occasionally staying on longer. It is scary, and I have to find someone here in Pittburgh who knows what they are doing.

[Guest]

mwirick,<BR> Hope you have given the car the Brake Tests at reatta.net? What year is it?