1979-1993 & 94 Conv [Subscribe to Daily Digest] |
 | [Main C900 Bulletin Board | BBFAQ |
Prev by Date | Next by Date | Post Followup ]
Member Login / Signup - Members see fewer ads. - Latest Member Gallery Photos
Re: Sudden change in cold start brake fluid pressurize time Posted by Ari [Email]  (#2847) [Profile/Gallery]
(more from Ari) on Mon, 20 Mar 2006 06:37:51
In Reply to: Sudden change in cold start brake fluid pressurize time, Eiron, Sun, 19 Mar 2006 12:42:17 Members do not see ads below this line. - Help Keep This Site Online - Signup |
It's interesting that you say "& I have no brake boost during that time". I assume that you get brake boost some time BEFORE the lights go out, but you don't have boost shortly after the car starts.
The ABS system pressure leaks down over time. The farther down it leaks, the longer it takes to pressurize the system, and consequently, how long it takes for the lights to go out. In my experience, even overnight, the system doesn't usually leak all the way down so that you get no boost shortly after engine start. So I wonder if one of the valves in the ABS system is a little leakier than usual.
A few questions-
Did you bleed the ABS system after you did the clutch work? They share the same reservoir, and it's possible you got some air into the brakes.
If you did bleed the system, have you done a brake flush? I wonder if work on the hydraulic system may have stirred up some dirt that got stuck in a valve.
I would bleed the brakes, and if you have done that since the recent work, I'd flush the brakes. Alternatively, you may have an ABS valve that's causing the system to leak down faster than normal. The only downside of that is that the ABS pump will have to run more often, which may or may not have an effect on it's life, depending on how often 'often' is. That could be an explaination of the suddend increase in time. Since the alternative is to start ripping into the ABS system and replacing expensive parts, I'd just live with it.
The ABS pump makes a hum. How loud it is depends on the pump and the car. It will typically sound like a hum that will be noticeable when it stops, which is about 10-30 seconds after the lights go out. The lights indicate the lowest acceptable pressure; the pump runs until the system is at full pressure. You can usually hear the pump only when the car is not moving and the engine at idle - I've never been able to hear it when the car is underway.
posted by 192.249....
, Mon, 20 Mar 2006 06:37:51 <-- Viewing This Message
No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.
 |
 |
 |
 |
 |
