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Re: AX Advice for Newbie--Brake Bleeding?

PostPosted: Fri Nov 13, 2009 3:26 pm
by JERRY B
Not required for auto x, The brakes don't get that hot. When you start doing D.E.'s you bleed them after each event.
Bleed at least once a year to prevent problems down the road. :rockon:

Re: AX Advice for Newbie--Brake Bleeding?

PostPosted: Fri Nov 13, 2009 5:37 pm
by ttweed
Marie-
No special need for bleeding for autox, as Jerry said, but I would "up" the maintenance interval on flushing the brake fluid to once per year.

Re: AX Advice for Newbie--Brake Bleeding?

PostPosted: Sat Nov 14, 2009 1:53 pm
by Kim Crosser
As someone who "boiled" his brakes at an AX (which then resulted in NO brakes on the next run :shock: ), I would HIGHLY recommend upgrading your brake fluid from the factory stock to a higher temperature fluid such as ATE. If you are staying with the factory fluid and you are driving aggressively, you should definitely get the brake fluid replaced at least each year.
The dealer shops (Pioneer, Hoehn) won't put in fluids that aren't on Porsche's official list due to Porsche rules, but any other shops will do it, and the dealer tech guys will concur that the stock fluid won't last too long if you are driving very aggressively.

Re: AX Advice for Newbie--Brake Bleeding?

PostPosted: Sat Nov 14, 2009 3:30 pm
by mrondeau
For AX, flush the brake system every year. If you are going to track the car, flush the system every 2-3 events, use an upgraded brake fluid and get rid of the dust shields to help with cooling. You may also want to upgrade your pads as well. Just my .02 (adjusted for the current economy). :D

Re: AX Advice for Newbie--Brake Bleeding?

PostPosted: Sat Nov 14, 2009 4:01 pm
by Dan Chambers
Kim Crosser wrote:As someone who "boiled" his brakes at an AX (which then resulted in NO brakes on the next run :shock: ), I would HIGHLY recommend upgrading your brake fluid from the factory stock to a higher temperature fluid such as ATE. If you are staying with the factory fluid and you are driving aggressively, you should definitely get the brake fluid replaced at least each year.
The dealer shops (Pioneer, Hoehn) won't put in fluids that aren't on Porsche's official list due to Porsche rules, but any other shops will do it, and the dealer tech guys will concur that the stock fluid won't last too long if you are driving very aggressively.


I would tend to lean more toward Kim's protocol for preventive maintenance. While some folks may think my regimen is excessive, I tend to bleed my brake system many times a year, whether AX-ing or TT-ing.

Because I change out my tires for track events the access is so easy that I just bleed the system every time ... or every other time at the least. Yes, some say that's too much. But, hey; brake fluid a year runs me no more than $20.00, and the practice of bleeding the system ensures a good inspection of the pads, rotors, bearing looseness, and overall health behind the tires/wheels while I'm down there. With a $49.00 Power-bleeder, it takes me an extra 15 minutes to set up the pressurized system, 5 minutes per wheel to bleed, and 5 minutes at the end to break-down the pressurized system. Voala! Done! Add an extra 40 minutes to a 30 minute wheel change-out and you have and hour-and-ten minutes of satisfying intimacy with the most important safety system in performance driving: the brakes.

Kim can probably tell you how scary it might be to be traveling very fast in a parking lot (with light posts, exposed Corner Workers, etc) and discover ... NO BRAKES! It happened once for me at a Q-DE when I first bought the car. YIKES! No thanks, never again.

If you are at all mechanically inclined bleeding the system is fairly easy. If you aren't mechanically inclined, a qualified shop can do the tire rotation and brake-bleed in about an hour ... 1.5 hours top. At the going rate that should run you around $150.00 Tops. Worth it? I think so. The best $300.00 a year could be invested in absolute confidence in your brakes.

Just my 2-cents.

Re: AX Advice for Newbie--Brake Bleeding?

PostPosted: Sun Nov 15, 2009 4:09 pm
by Dan Chambers
mariegrosjean wrote: Can I tell by the brake fluid level at all, or are there any other "warning" signs?


One way is by checking the color. If you're using a typical DOT 4 fluid and it's "tea" colored, it will tend to go dark to black over time and many heat cycles. If your reservoir is getting dark, you're due for a change. Keep in mind the "gunk" that collects in the brake fluid often falls downward to the calipers where you can't see it. So if the fluid is turning color in the reservoir, the fluid in your calipers may be ..... :shock: :bigcry: !

Time is your other enemy. The longer the time, the more degraded your fluid. Do you live near the beach or bay? Even more problematic. Once a year for a complete bleed is good. Twice a year is better.

If you notice your brake pedal going soft after a couple of laps of hard braking ... it's time.

I really like the ATE Blue and Ate Gold for intense driving events. I know Dealer Service departments tend to steer away from these fluid and that's why I recommend a service provider like Black Forest, Dieters, and Mirage. With your splash guards on the back of the rotors (that tend to trap heat) you're going to be giving your brake fluid a real work-out.

As a side note, I've had more than one service provider ask me who does my brakes ... "the firmness of the pedal is really impressive." The answer: "I do them myself." When it comes to brakes, I leave nothing to doubt ( and .... Anthony at Black Forest does one heck of a great job on caliper rebuilds :wink: ).

That's one driver's opinion. Others may vary.

Re: AX Advice for Newbie--Brake Bleeding?

PostPosted: Sun Nov 15, 2009 5:28 pm
by martinreinhardt
I agree and as part of my checklist, I do bleed my brakes and top off the brake fluid before every big track and every other or so Autocross event.

If you run Autocrosses, DEs, Time Trials or Club Races you shouldn't waste your time or money on OEM brake fluid, go directly to "ATE Super Blue Racing DOT4" or similar. You can't spend too much on safety and peace of mind in racing.

Just like Kim, in the past I also ran out of brakes with regular OEM brake fluid. Since that day, every one of my street and race cars has ATE or AP racing brake fluid in them and I have had no issues since.

Re: AX Advice for Newbie--Brake Bleeding?

PostPosted: Sun Nov 15, 2009 6:21 pm
by Kim Crosser
mariegrosjean wrote:So the only indication you're not doing brake bleeding enough is that you completely lose all braking like Kim? Can I tell by the brake fluid level at all, or are there any other "warning" signs?

In my case, there was no warning. I went from great Porsche braking to ZERO brakes in one lap. I had a couple of pretty big spins, where I was standing on the brakes. On the last "normal" lap, near the finish I did a full 180 at speed and slid backwards a ways with the brakes full on. Got back on the course, got in line, took off up the hill (clockwise course) - very little braking required in the first sections - got onto a big straight across the top of the West lot - into high 3rd gear (85+) - went for the brakes in the NE corner right-hander and the pedal just thudded to the floor with no effect. :shock: :shock: :shock:
Luckily, we don't run our courses very deep into that corner, so after I flashed past the corner worker and through the cones, before I ran out of parking lot I was able to stop by rapidly pumping the brake pedal and pulling on the hand brake.
After discussions with others ("So, when did you last have your brake fluid flushed and refilled?" :oops: ), I switched to ATE at Black Forest - no problems since.
Bleeding periodically is good, but fully replacing your brake fluid every year is a very inexpensive insurance policy against losing your brakes at the wrong time, and you cannot count on having any warning.

Re: AX Advice for Newbie--Brake Bleeding?

PostPosted: Sun Nov 15, 2009 6:37 pm
by ChuckS
Marie - one additional thought.
You might think that the Porsche dealer is changing your brake fluid when you take it in for it's "annual" check up. I found out the hard way that they are only "checking" the fluid and topping up the resevoir if it is low, not changing it. (for what they charge, they should be changing it!) So, your brake fluid could still be what Porsche put in it at the factory unless you have specifically had them flush and change the fluid.

Re: AX Advice for Newbie--Brake Bleeding?

PostPosted: Sun Nov 15, 2009 7:52 pm
by SDGT3
Two thoughts on this subject:

1. If you ever decide to do our entry level DE at Qualcomm, definitely have fresh fluid. I've never had the brake pedal go soft in my car, whether it was an AX, DE or TT except at the Qualcomm DE. The combination of high speed (for a Q event), hard braking (expecially coming down the hill from Friars Road toward the trolley bridge), 25 minutes continuous lapping sessions and not enough long straights to sufficietly cool the brakes contributed to this.

2. Whether you have someone change the fluid for you or you do it yourself and elect to go with the ATE fluid, alternate between the ATE Super Blue and the Amber colored fluid every other change. They are basically the same in terms of boiling points and cost. The reason for this is that you can see when the old fluid is out of the system and the new fluid in ensuring you've got the old stuff out.

Re: AX Advice for Newbie--Brake Bleeding?

PostPosted: Wed Dec 09, 2009 12:15 am
by UKAYMAN
Add me to the list of requiring brake bleeding or fluid upgrade to a performance grade.

Three autocrosses in on my new car, with the most recent one at El Toro last Sunday, I boiled my brakes in the second practice session. In the timed runs session during the warm up lap the brake feel felt a little too soft for my liking, or I was just paranoid after reading what Kim C and Martin R had experienced after boiling their brakes, so I took it a little easier on the heavy brake zones. In my efforts to catch the fast Cayman drivers, and knowing they were going with a fresh set of R compounds for timed runs I think I pushed too hard. I never had this problem before, or noticed it before with the previous Caymans using stock fluids, but fluid has leaked out from or into some overspill area and it looks like there is moisture/condensation inside the reservoir. I notice the cap says to use DOT 4 only fluids. Is racing fluid DOT 4?

I guess, next stop Dieters or Black Forest for an evaluation.

Re: AX Advice for Newbie--Brake Bleeding?

PostPosted: Mon Dec 14, 2009 9:22 am
by Kim Crosser
UKAYMAN wrote:Is racing fluid DOT 4?

ATE brake fluids (Blue or Gold) are DOT 4. I am not sure if all fluids are DOT 4.