Bodhi

Just got back from a Driver's Education event at Thunderhill, where I got the 997 out on the track for the first time. Wow. Great car.

Anyway, I'm concerned that I may have boiled away an appreciable amount of brake fluid. The brake warning light never came on; and I did have decent stopping power all day. Beyond using the brakes really heavily during each session, it was really hot out at Thunderhill that day (90-100 degrees). Right now the brakes don't feel all that bad, but they do feel a bit spongy relative to before the DE.

When I checked the brake fluid reservoir today, it was difficult to tell what's going on. Have to admit I don't have much experience or knowledge in this area.

So, my questions:
1) what color is the brake fluid that comes stock with the car? It is somewhat difficult to tell whether the reservoir is completely empty. The reservoir is housed in a plastic case that allows you to look at the top, and has a small (not so great) peep hole to see what's going on at the side. If the fluid is clear, then the seam of the reservoir container lies between the min/max markers, which makes it all the more difficult to tell.

2) is it common to lose brake fluid at DEs? I was not shy about braking hard. The instructors gave me some great tips about how to apply the brakes hard, but gradually.

3) the manual says to use "ONLY ORIGINAL PORSCHE BRAKE FLUID". Why can't I use any decent DOT 4 fluid? what a hassle to have to go back to the dealer. Thoughts? Any recommendations on decent brake fluid?

4) sounds like a smart thing to do from time to time is flush the brake fluid. How often should I do this? Before every DE? every couple DEs?

Thanks in advance for the advice.

ltc

I don't think you lost any brake fluid, but you may have boiled your fluid (simply put, the heat generated down by the calipers causes any atmospheric moisture in the fluid to boil, hence changing the hydraulic compressibility of the fluid). When you "boil" or "cook" your brake/brake fluid, nothing is lost nor vented into the atmosphere.
If you were leaking/losing brake fluid, you should find it once parked or when the car is up on the lift.

As part of most normal PCA DE tech inspections (prior to the event, at an authorized tech center/mechanic), you will be asked when the last time the fluid was CHANGED/FLUSHED and when the last time the brakes were BLED. This is normally on the form (at least in my home NER region)

You normally change your fluid at least once a year and bleed the brakes before each event (and sometimes between runs).

Normal Porsche brake fluid is light gold/yellow in color.

As far as other types of fluids, there are many options; a search of this forum will yield numerous threads and discussions. These DOT4 fluids simply have higher boiling points (dry and wet...wet is the more meaningful number).
There is ATE Blue and ATE Gold for about $10/litre (same fluid/properties, just one has a dye (Blue) and one doesn't; this makes flushing the system easier, as you know when the color changes, you've flushed the entire system; ranging all the way up to Castrol SRF for about $70/litre.
(FWIW, I run Castrol SRF in my Cup car....as I am VERY fond of my brakes )
Any questions....just post and someone will be happy to help I'm sure.

Best of luck and enjoy DE!

Renn 951

PCA Potomac requires brake fluid to be changed every 3 months for DE, but with ATE Blue or Gold you are allowed to go 6 months. The problem with most OEM fluids is they won't stand up to heavy track use because the boiling temp is too low. If you intend to do more track events you should change to a heavy duty racing fluid like th ATE.

Now if you really boiled your fluid this weekend I think you'd know because you'd feel a REALLY spongy pedal when braking hard. What you're describing could be just due to having worn your stock pads down with the hard braking, so you'll feel more pedal travel now than you did before the event.

mooty

bodhi, i was there at TH as well. which 997 were you?

low fluid: you may have boiled it or sometimes when you use up lots of your pad, the fluid level will be lower as the pads get thinner.

dealers differ in their maintenace opionions. my dealer couldn't care less what fluid i put in the car. your best bet is to put motul 600, ate blue, ap racing fluid or Castrol SRF.

you should bleed the brakes before each event. and if you feel you boilded the fluid, bleed after as well. usually you don't flush the whole system. a good bleed is enough. i would flush it at least once a year.

Bodhi

Hey Mooty,
I have the seal gray, base Carrera. It attended the DE on 7/28.

I'm planning on heading back to TH for the tracquest event, but need to sort this out before I go.

I live in SF. WHere would you recommend that I take the car to have the pads checked, brakes bled, etc.?

mooty

bodhi, you have PM

dnitake

I was at Thunderhill (hot!!) as well this weekend. Don't know if you have stock brake pads, but I had the same impression w/ my brakes the last time I was there. I boiled the fluid which became very apparent on the cooldown. Pedal to the floor w/ little effect. The stock pads worked fine for me at the track but wear down really quickly. I wore down about 50% of the pads in 2 days. Thiings didin't feel as tight w/ the brakes. Flushed w/ stock Pentosin, switched to Pagids and didn't have any issue in this last scorcher. Maybe because the Pagids don't wear down as quickly, and maybe because I stopped trying to threshold brake.

Capt. Carrera

Translucent amber

You don't loose brake fluid. What has happens is you lose pad. Think about it. As the pads wear, the pistons in the caliper extend, increasing the fluid volume within the calipers.

I'd use ATE Super blue, or ATE 200. (The only difference is one has blue dye in it.) It's a good DOT 4 fluid that will work with ABS.

At a minimum, I bleed a bit of fluid from each caliper for every two track days. Every fourth day, I'll flush the entire system. If I'm flushing Super Blue, I'll replace with ATE 200. That way I can visually tell when the old fluid is flushed.


Hope this info helps!

Bodhi

Hey All. Thanks for all the great advice.

Dnitake, You mentioned using pagid's. Which ones? How are they for street driving?

dnitake

Bodhi,
Pagid Orange, and while they are good enough when cold on the street, I wouldn't recommend them for the street as they squeal pretty heavily. They are also relatively expensive compared to stock. It only takes 30 minutes to change them all except when they are brand new.And most of that time is jacking up and dealing w/ the tires.
Plan on a 2 hours if they are new.
1) They fit VERY snugly when new. I wouldn't bother w/ the anti-squeal plate which will make life a LOT easier. Just generally mucking about for the first time trying to get them to fit takes time.
2) Also I drilled the holes for the sensor originally thinking I could keep them on for the street. Don't bother, just zip tie them off in a safe place.
3) You need to bed them. Search for "bedding new pads". They will smell like burning brakes until you get them properly bedded. This is normal.
4) Don't expect to feel a huge improvement at the track over stock. They just work like they're supposed to all day. Switching to a higher temp fluid is a very good idea. I had boiling problems for back to back sessions and felt the pedal go to the floor while lining up for the 3rd consecutive session. Pumping them brought them back to normal after a fashion, but I won't do 3 sessions in a row again at least in 100 degree heat. No point. Tires get too hot as well.
5) Finally after the first run of the day, check your lug nuts. The heat cycling can cause them to back off. At least check them before you drive home on cold rims. Don't ask me how I know.

I am new to this as well, so heed the heavyweights here on this board.
Just my 2 cents,
Dan

mooty

Pagid orange may or may not squeal on street. on one of my 996, they do, no matter what i did to it. on my other 996, they never squeak once i bed them.

if you plan to change pads b/n track and street, invest in a good impact wrench. it's much much much faster. the price is well worth the anguish you dont have to go through.

actually my pagids (yellow as well as orange) both got much better bite than stock pads. and i use them on street as well as track.

i would check lug nuts every session and use a torque wrench, don't muscle it.

pagid yellow cost a tad more than orange, with slightly less bite, but 2x the life.

Bodhi

Are pagid yellows less likely to squeal on street?

Tom W

If you plan on doing more DE events, rather than worry too much about what shop to take your car to, find another local Rennlister to help you learn to DIY. There will be many times where you will want to check your pads/brakes while at the track. There are usually enough of us there to help you too (with tools or fluid).

I was also out at Thunderhill on Friday and Saturday. My car is the one that had the engine go ka-boom during the exhibition race on Saturday.

ceboyd

in our 993, the pagid ORANGE made just as much noise.... and the pagid blacks.. well, they could almost wake the dead!!! ..but I love them on the track!!!!

forklift

When I drive my car to the track I feel sorry for the cars next to me with the windows down so I use the parking brake for that last little bit sometimes...but the blacks are worth it on the track.