[Yanbags]

Originally Posted by Infern0

I have a friend that also has a track day coming up. He's been swamped with work and may not get a chance to change out stock fluid before the event. I'm thinking he may be OK with stock fluid in a novice group HPDE. Right?

Same with 5w30 oil?

Again, asking for a friend.

Is it OK? Possibly. I don't think it's worth the risk. The last thing he wants is for his brakes to take a shit on a hard brake zone or have the pedal go to the floor and cut an expensive track day short.

Oil becomes a warranty question should things go awry. It's specified for a reason - just not meant to see such high temps.

[Infern0]

Originally Posted by Yanbags

Is it OK? Possibly. I don't think it's worth the risk. The last thing he wants is for his brakes to take a shit on a hard brake zone or have the pedal go to the floor and cut an expensive track day short.

Oil becomes a warranty question should things go awry. It's specified for a reason - just not meant to see such high temps.

I think my buddy already knew the answer (which you gave) but was hoping for a little relief.

He got the oil changed just in time but ran stock brake fluid (but took a power bleeder and Motul to the track just in case). No brake fatigue at all, even braking from 145ish in the back straight of COTA. Pretty impressive.

Thanks for pressing the oil change.

[Corbu]

Quick question about the track Dot 4 stuff : After a track day, can DOT4 fluid be left in the system or does it have to be swapped back to DOT3?

[Junkyardspecial]

It can stay in, its now your new fluid. DOT 3 is pretty much just a place holder fluid.

[rlarsen462]

If you use SRF I've been told it's good for up to 2 years depending on your climate. I plan to flush the SRF annually regardless.

[PROMETHEUS]

I use Castrol SRF and change it at the beginning of track season every year. It has never let me down.

[Apexslayer]

The Motul and Castrol perform equally well on the track, though the specs indicate the Castrol is slightly better in wet and dry performance. The big difference is the Castrol will definitely last 1 year or more (I change every year anyway), while the motul may require bleeding between every one or two track weekends

[Biscuit.fr]

Motul :
Why 600 and not 660?
What’s the difference?
I put 660 in mine, should I regret and switch back to 600 next time?

Hydroscopic mentioned higher for dot4...
How do we know it’s Time to reflush?

BTW,
How long can the dot4 stay in the can?
Opened / not opened yet
Didn’t check if there is a max to use date...
Because of this hydroscopic power...

[CamaroKid300]

I'm about to switch to DOT 4 and I think I'm going to go with the Castrol SRF so i can go a little longer between changes.

Great thread, thank you.

[hammdo]

This is what I use to flush brakes now:

https://www.amazon.com/gp/aw/d/B00OM...b_b_asin_title

-Don

[Canadian ZL1]

Originally Posted by Eric SS

Dot 4 is not only ok, it is recommended by GM if you plan on tracking it.
I use Motul RBF600

Thats is what I will be using as well. It will be worth changing for the track usage.