I spent 8:30-4:30 at Summit Point raceway in WV (http://www.summitpoint-raceway.com) yesterday for "Friday At The Track" (my first time!). Had my A4 1.8tqm (wett chipped) out for 5 20-minute runs on the 2 mile, 10 turn track, and it performed great. However, by the end of the day, the brakes were not responding too well (stock brakes/pads). I'd have to push the pedal pretty far towards the floor to get brake power. I don't know much (ok -- anything!) about brakes. I figured maybe it was because they were so hot (and the fluid), but today, after sitting in my garage all night, the brakes still don't feel as good as they did before I went onto the track. Any ideas what the story is? I've bought some hi-temp fluid, but I need to figure out how to drain the existing fluid. I'll probably get better pads in the future too. Will that solve my current problem?<p>Thanks!<p>PS: Only went off the track once -- went into turn 5 way too fast. Doh! Don't think there were any serious incidents or car-car contact mishaps at the track all day, which is good.<ul><li><a href="http://fischer.mike.org/drive/">My A4 Page</a></li></ul>
10-24-1998, 01:07 PM
I think you got some air in your brake lines. I would at minimum bleed the brakes at all four wheels. Best option would be to install some ATE super blue brake fluid, or equivalent, and then bleed the brakes. I am about to go one step farther...today I installed the Brembo brake rotors, and in the next two week or so I will be putting in steel braided brake lines and the super blue stuff. I better be set after all this money and labor. I experienced the same loss of brake power when I went on track last time...not a fun feeling huh....kinda hard to late brake.<p>Steve S.<br>97 2.8QM<p>
10-25-1998, 08:07 PM
Slightly modified suggestion I might make from abou.jt 15 years of track events with the Porsche Club:<p>1) Use the ATE Typ 200 fluid rather than the Super Blue- same high temp performance, same price, only is clear so it doesn't stain anything ands everything it contacts a deep blue!<p>2) The biggest thing that made a difference in my Porsche 911s was to duct cool air into the rotors. The Porsche aftermarket houses sell ducts that mount under the A-arm, and have a flexible cooling line running from them to the eye of the the rotors thru the brake backing plate. Present 993 that I have has the duct ending right under the caliper, but the car does have drilled rotors. Don't know if the front driveshafts preclude this fix on an A4 or not, but if it is available, HIGHLY rtecommend this as the next step besides fluid.<p>Also, stock pads can break up under hard use (if you pull your pads and look at them, I bet that the lining shows cracks/flakes from hard use). Might want to switch to a carbon kevlar pad like offered by Weston Motorsports (610/558-0631 or E-mail at WMS Brakes@aol.com) <br>
10-26-1998, 07:40 AM
Ray is dead on. Definitely get some air to the front brakes. Zip ties and flexible ducting, an angled diverter from the center pan, and very open wheels all help.<p>The Ate/super are actually designed to alternate, so you can tell when the new fluid makes it to the nipple. Brake fluid is an excellent solvent, so don't get it anywhere.
10-28-1998, 01:10 PM
I understand the process of bleeding the brakes in order. But, I was wondering if you used a different procedure for replacing the brake fluid.<p>Do you just drain it from each valve in sequence or do you have to have all of the valves open? Are there any other tips or caveats?<p>Sorry if this is a stupid question, but I'm still learning.<p>TIA,<br>Jim
10-29-1998, 08:47 AM
Not a dumb q at all. Esp. since the stupid shop manual is so expensive if you can find it at all.<p>Everyone has their own ideas on this, but I bleed the brakes pretty frequently (every 2 ax's), so there is not any old fluid in the system. Most brake fluid companies (depening on the DOT number) say bleedem'every 2 years. That sounds about right to me. <p>When I help friends, I take a big turkey baster and pull the old fluid out (down to about 1/2-2/3 way on the master cyl. Then I add NEW fluid up to the top, drawing down the fluid from the bottom of the two cups each time. So, most of the new fluid is in the master now, and I didn't drop the level too low. <p>Then I bleed it, and add to the master repeatedly (so it doesn't get too low). You can generally see the fluid change color at each caliper if it is old (best to use the alternating color ate). You can probably be equally effective without the turkey baster, but I am a little detail-oriented.
10-29-1998, 10:13 AM
When replacing the brake fluid, do you drain it from each caliper simultaneously or one at a time (in the same order you would bleed them)?<p>Thanks,<br>Jim
10-29-1998, 02:42 PM
Same rotation. You are essentially bleeding the system. There are "speed bleeders," which make a world of difference, but their web site is down. So, I can't get some to put on my A4.