Brake Fluid Change Interval for HPDE events?

[lonepatrone]

How often do you change your High Temp Brake Fluid? I have a 3100 lb. MKV GTI with stock rotors and calipers and Hawk HP+ brake pads, and Pentosin racing fluid. I'm on street tires right now, Bridgestone Potenza RE050's. The pads only have 120 minutes of track time (6-20 minute sessions) and minimal street mileage. On the last track session the brake pedal felt a little softer than the first session.

 

Another quick question, I know a good pyrometer with a probe is the way to go for measuring tire and rotor temperatures, but they are expensive at a minimum $100 for a cheap one. Do you think there is value in buying an infrared thermometer gun from harborfreight.com for $28. Granted you only get surface temp readings where as the probe will give you a better radiant heat reading, but $28 is easier to swallow than $100. This racing stuff is expensive. I better get used to bringing home the wife more flowers to detract from the growing collection of racing gear.

[gobuffs]

Your problem is with the pads and not the fluid. HP+ pads are not track pads. Get some real track pads even it it means swapping pads back and forth.

 

Generally you need to flush your fluid every 6 months.

 

Infrared pyrometers are not worth the money.

 

And yes, track is more expensive than illegal drugs.

[jimbow]

Are you smelling your pads after a couple laps?

That brake smell is very distinctive.

If so bleed at the end of each day and flush after 2 or 3 events.

 

I'm using Hawk Blues on my Mustang and my brakes get HOT. I bleed each day and get dark gray fluid from the fronts, rears are a real light gray. If I have time between events I'll do a full flush, been averaging every other event so far this year. I'm also running time trials, trying to go as fast as I can for as long as I can so when I use the brakes - I use the brakes.

[obzezzed350]

I bleed mine after every 2 day event, and flush every other. I run Motul 660 fluid.

[Meat]

Just to clarify, there are 2 types of brake failure from overheating- brake fade which occurs when the pad overheats, and a soft pedal that occurs when the fluid overheats. Sometimes you get both at the same time.

 

I've had good success with ATE Super Blue fluid. I bleed the brakes before every event and flush the fluid every 4 events or so, depending on if I start to feel any fade in the pedal at any point.

 

I found that removing the front dust shields on our cars makes a great improvement in the longevity of the fluid. Those shields hold in a lot of heat and removing them helped rid me of 80% of the fade and soft pedal I would occasionally feel late in a session.

 

I am currently running Carbotech XP12 and XP8 pads on the track. The HP+ pads will be alright when you're just starting out, but after a few events you will start to overcook them and they will fade on you.

[obzezzed350]

+1 on the dust shields, cut those things out!

[lonepatrone]

Greg,

 

Thanks for the info. FWIW, a shop that I get some parts from advised against me using ATE Super Blue. They said the dye in the fluid does not interact well with the seals in the MKV GTI brake system, and will create a squeaking sound over time. On the other hand, I've heard you can't go wrong with ATE, but I thought I would share. Thanks again for the info.

 

Pete

[obzezzed350]

Ive always just gone with Motul RBF600, has a higher boiling point and isnt much more expensive.

[kbrew8991]

thats probably the same guy that will tell you OEM pads are better for track use. Don't listen to him anymore

[getfast]

FWIW, a shop that I get some parts from advised against me using ATE Super Blue. They said the dye in the fluid does not interact well with the seals in the MKV GTI brake system, and will create a squeaking sound over time. On the other hand, I've heard you can't go wrong with ATE, but I thought I would share. Thanks again for the info.

 

Pete

 

I have heard this from some R32 guys as well. Interesting how the stuff works fine in all other german cars though...

 

Also, ATE makes the same stuff but gold not blue ( http://www.tirerack.com/brakes/ate/ate_type200_amber.jsp ), if the blue dye is the problem specifically.

[Keith]

On my old 3300lb CMC car with factory brakes, I changed fluid once a season at the start of the season and that was it (2004-2008). I completely changed the fluid at the start of the season with 2 liters of Castrol SRF and was able to convert bleeding time at the track to more useful endeavors like eating extra burgers and talking to other drivers...

 

While SRF is expensive for a fill, a fill lasts a long, long time.

[chuck hannah]

...not sure on your experience level but proper braking takes you quite a long way too.

if this is your first event then your instructor will guide you...use the brakes "late" and firm, gradually applying the brakes can overheat even the best. i'd flush every 4-5 days of track driving.