Does the 991 have high temp brake fluid?
05-21-2015, 06:36 PM
#1
Does the 991 have high temp brake fluid?
It's been a long time coming, but I'm finally taking my 911 to the track. Part of the checklist for 1st timers is having high temperature brake fluid
http://performancedrivinggroup.com/firsttimers/
I just had my car serviced so I'm assuming the other items will be ok. The only other one I was worried about was the tire pressure. Should I make any adjustments to it?
http://performancedrivinggroup.com/firsttimers/
I just had my car serviced so I'm assuming the other items will be ok. The only other one I was worried about was the tire pressure. Should I make any adjustments to it?
05-21-2015, 06:59 PM
#2
Race Car
Join Date: Oct 2002
Location: Fairfax County, Virginia
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I doubt you have high-spec brake fluid in your 991 from the factory, but the good news is if you are new to track days you will never get the brake hot enough to boil the fluid, if you do - then you would be the first time I'm ever seen a novice do it in 19 years of being a HPDE Instructor. Likely you will not drive the car hard enough to even smoke the pads at first.
Brake Fluid is Hydroscopic, which means over time it absorbs moisture (water) and that lowers the boiling point of the fluid. That's why track rats are encouraged to change brake fluid every 6 months, to keep it fresh and the temp rating up. Check the boiling points of any brand you care to run, higher boil point product costs more, simple as that. If you brake fluid DOES boil, then you will lose your brakes, which really sucks when coming off a main straight
I drive a car pretty hard on the track. I have never boiled my brakes and have never run anything more exotic than ATE Blue or Gold fluid. I change my brake fluid with my MityVac once a year if doing track events, every two years if not.
Brake Fluid is Hydroscopic, which means over time it absorbs moisture (water) and that lowers the boiling point of the fluid. That's why track rats are encouraged to change brake fluid every 6 months, to keep it fresh and the temp rating up. Check the boiling points of any brand you care to run, higher boil point product costs more, simple as that. If you brake fluid DOES boil, then you will lose your brakes, which really sucks when coming off a main straight
I drive a car pretty hard on the track. I have never boiled my brakes and have never run anything more exotic than ATE Blue or Gold fluid. I change my brake fluid with my MityVac once a year if doing track events, every two years if not.
05-21-2015, 08:08 PM
#3
In the same way Duane said you're unlikely to overheat your brakes, your tires probably won't run a lot hotter either. But, they will definitely tend to heat up as the day goes along. Presumably you are running something like 30/34 to 33/37. So just check immediately after each run and bleed out whatever it takes to maintain your normal level as the day goes along. Whatever you do, avoid getting up in the 40's, as that's where they really start losing traction.
05-22-2015, 02:08 PM
#4
Burning Brakes
Pretty much what the dr said. He is talking about DOT 4 fluids. I also use the swap-color ATE product. Sadly Blue is no longer available in the US. Deemed a non-conforming color.
If you feel you really heat soaked the brakes during multiple sessions with high speeds, or sessions lasting longer than 20 minutes you can do a quick bleed to get rid of the contaminated fluid. You only need a few simple items.
It takes 2 people 5 minutes. You are only extracting a small amount from each caliper. Just enough material to run clear.
Remember to check fluid often while bleeding and ALWAYS remember to put the cap on the MC before touching the brake pedal....(the geiser) hehehe.
Hope this helps.
Tire pressure. Ambient and track temp are the first component. Ask an experienced instructor where your starting pressure should be. Buy a good gauge and torque wrench.
Have fun!!!!!
If you feel you really heat soaked the brakes during multiple sessions with high speeds, or sessions lasting longer than 20 minutes you can do a quick bleed to get rid of the contaminated fluid. You only need a few simple items.
It takes 2 people 5 minutes. You are only extracting a small amount from each caliper. Just enough material to run clear.
Remember to check fluid often while bleeding and ALWAYS remember to put the cap on the MC before touching the brake pedal....(the geiser) hehehe.
Hope this helps.
Tire pressure. Ambient and track temp are the first component. Ask an experienced instructor where your starting pressure should be. Buy a good gauge and torque wrench.
Have fun!!!!!