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Re: question regarding ABS. 92 cvt. Posted by Ari [Email]  (#2847) [Profile/Gallery]
(more from Ari) on Fri, 25 May 2001 12:30:34
In Reply to: question regarding ABS. 92 cvt., chrisx, Fri, 25 May 2001 11:57:09 Members do not see ads below this line. - Help Keep This Site Online - Signup |
When you first start the car, you get the Anti-lock (ABS) and Brake Fluid lights. They stay on until the system hits a minimum pressure. At that point, the Brake Fluid light goes out. The Anti-lock goes out a moment later, because it's doing some other self-tests. The ABS pump will continue to run to fully pressurize the system.
The amount of time the lights stay on varies. When the car is shut off, pressure leaks down. The more time, the more pressure leaks down. So it will take longer to pressurize the system after the car has been sitting for hours than if it was shut off an hour before.
As cars get older, the time to pressurize increases. A newer car will turn the lights out in a matter of 5 seconds or so. With an older car, 30 or even 45 seconds isn't uncommon with a car sitting overnight. As long as the lights go out, you're fine. I guess if they took a couple of minutes, then I'd start worrying.
Changing the brake fluid sometimes speeds up the pressurization time. Sometimes not. But Brake fluid should be replaced every 2 to 3 years, period.
Some of the things that influence how long it takes to pressurize the system are how long the car has been shut off, temperature under the hood (affects leakage, pump speed, fluid viscosity), charging system condition (voltage affects pump speed), and state of the ABS pump. Since a lot goes into it, you can't really point to any one thing.
5 seconds or so with a recently turned-off car, up to 30-45 seconds with a car sitting overnight. As long as the lights NEVER come on while driving, you're OK.
Also - don't drive off until both lights go out. ABS pressure is used to provide brake boost. If there were a failure and the system didn't pressurize, the lights would stay on. If you drove off with no pressure in the system, you'd have no brake boost, and your stopping distances would increase by a factor of three or four. Chances are good you'd slam into the back of something. So wait for those lights to go out!
, Fri, 25 May 2001 12:30:34 <-- Viewing This Message, Fri, 25 May 2001 15:05:25
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