1985-1998 [Subscribe to Daily Digest] |
 | [Main 9000 Bulletin Board | BBFAQ |
Prev by Date | Next by Date | Post Followup ]
Member Login / Signup - Members see fewer ads. - Latest Member Gallery Photos
Don't, and why Posted by Ari [Email]  (#2847) [Profile/Gallery]
(more from Ari) on Wed, 4 Sep 2002 08:59:01
In Reply to: Brake Fluid Reservoir Level?, John P, Tue, 3 Sep 2002 12:34:17 Members do not see ads below this line. - Help Keep This Site Online - Signup |
A couple of things-
Notice that the brake fluid level is "Full With Charged Accumulator". The proper way to check the brake fluid level is to start the car and let it idle until the ABS pump stops running. This will be about 15-20 seconds after the ABS and Brake Fluid lights go out. If the level is below that FULL line, add fluid. It should be no higher. OK, a quarter of an inch is OK, but not more.
If you let the car sit overnight and check the level before starting the car, you'll see that the level is well ABOVE the FULL line. That's normal. When you start the car, the ABS pump runs and pressurizes an accumulator for the ABS and Brake Boost. It pumps fluid out of the reservoir, so the level drops. When the car is sitting off, the accumulator leaks down, and the fluid level in the reservoir rises.
With normal fluid levels, when the accumulator leaks down, the Brake Fluid reservoir is almost full. As the level rises, it replenishes the clutch portion, assuming there was some loss in the clutch circuit.
If you OVERFILL the reservoir - run higher than the Full line when the accumulator is charged - when the accumulator leaks down, the fluid level will rise above the top of the reservoir. Depending on the state of the venting, it will either leak out of the reservoir (and ruin your paintwork), or pressurize the reservoir, which isn't designed to be pressurized, creating a leak, and then ruining both the paintwork and reservoir. So don't overfill.
Which begs the question - why did Saab design it this way? Very simple. Brakes are more important to safety than the clutch. If your clutch slave cylinder were to leak massively, it will drain all the fluid from the clutch system. If there wasn't that dividing line between the brake and clutch reservoirs, a failure of the clutch system would drain the brake system, and you'd have no brakes.
posted by 140.157.4...
, Wed, 4 Sep 2002 08:59:01 <-- 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.
 |
 |
 |
 |
 |
