Boiled Brake Fluid - Seeking Advice

[MoreAgain]

I boiled my brake fluid (Motul 600) at Streets of Willow in my LR RWD Model 3 on a 104 degree day three weeks ago. It happened at about 40 minutes into the first session during a Time Trial training exercise. We were using a small section of the track with a lot of tight braking zones and only one short straight. I let the car sit for a hour after the session and had no further braking problems for the remaining 3 sessions that day, although none of the other sessions were as brake-intensive. The reservoir still looks full. The fluid was added at the same time I changed from the stock front rotors to the larger MPP rotors, about 6 weeks before the event. This was the first track event with the new rotors and fluid.

I really haven't thought about it since and have had no issues for daily driving over the last three weeks. But, now I'm getting ready for TeslaCorsa this coming weekend at Buttonwillow. Looking for advice on next steps. I'm thinking of just bleeding the brakes to ensure there are no air bubbles and leaving it at that. Or should I do a full flush. I have another bottle of Motul 600, but if I'm doing the full flush, should I try the 660 instead, or event Castrol SRF. Anything other recommendations?

Thanks!

 

[MTSN]

I would definitely bleed at least, but a full flush isn't a bad idea since the conditions were "extreme" with the high heat and boiling event. Are you running stock pads and rotors?

 

[MoreAgain]

I would definitely bleed at least, but a full flush isn't a bad idea since the conditions were "extreme" with the high heat and boiling event. Are you running stock pads and rotors?

I know you're right, but I'm trying to avoid replacing the fluid. I had the MPP 365mm front rotors, MPP Track pads, and new brake fluid installed about 6 weeks before the event. This was the first event with the new brake set-up.

 

[Alpaca]

Regular Motul has 522F boiling point (dry) ? I used to use ATE200 on my track car - not much higher - never boiled it ! But 660 will give you about 100 degrees more - better than hitting the wall

 

[Rottenapplr]

How does the brakes system maintenance work with the tesla model 3. Because the manual says to not add any fluid (I think that’s what I read). I work on my past cars so I’m wary about opening my brakes in the model 3 after reading the manual. Can you just add fluid like a regular car? How about changing the pads? Do you need to compress the position to push back the caliper Pistons?

 

[Davidss2]

Are you sure you didn't get pad fade instead of boiling the fluid? Getting pad fade on the M3 is pretty easy even with upgraded pads. Was the pedal hard but the car was not stopping? Or the pedal went completely to the floor?

 

[hocr]

Rotors and fluid couldn’t handle 104 degrees?

 

[Mbrockus]

Rotors and fluid couldn’t handle 104 degrees?

Its not the ambient temperature that is causing the issue. When the OP was on the track and doing heavy braking it generated a lot of heat in the brake system that was most likely absorbed by the calipers and transferred to the fluid. This would be the cause for the fluid to lose its effectiveness.

 

[jmaddr]

The TM3 is a heavy car, no way around that. And if you have a heavy braking track without long straights to cool them down, your only options are higher boiling point brake fluids, BBKs for more heat absorption, or some brake ducting.

I would swap out your fluid if it's failed once. Fluid can absorb significant water over time...though 6 weeks is pretty short. Maybe you had a bad batch of fluid or potentially if the fluid change was in humid temperatures or the fluid was left open exposed for some time...again pretty weak...but if present that water can turn to steam pretty easily which is what most people feel when they say their fluid "boiled". I have a hard time believing you exceeded the dry boiling point of 600 unless perhaps you were doing repeated 120-40 mph stops on track tires.

The more water saturated the fluid, the more important the wet boiling point is. The wet BP is usually over 200 degrees F less than the dry BP so it's paramount there is no water in there, which is why you should change it at least yearly.

If you want insurance, 660 is about is as good as it gets for us mortal with budgets.

 

[destructure00]

What pads were you using? If stock, it's likely that you glazed the pads. Have you looked at them? My stockers were trashed after my first track day.

 

[Zcd1]

BTDT with both versions of Motul fluid.

Go with Castrol SRF - it’s worth the extra $$. (speaking from personal experience)

 

[MoreAgain]

Are you sure you didn't get pad fade instead of boiling the fluid? Getting pad fade on the M3 is pretty easy even with upgraded pads. Was the pedal hard but the car was not stopping? Or the pedal went completely to the floor?

No, the pads are new MPP Track pads. They still look great. The pedal went all the way to the floor and the smell was dead give-away.

 

[MountainPass]

Castrol SRF!!!

 

[MoreAgain]

The TM3 is a heavy car, no way around that. And if you have a heavy braking track without long straights to cool them down, your only options are higher boiling point brake fluids, BBKs for more heat absorption, or some brake ducting.

I would swap out your fluid if it's failed once. Fluid can absorb significant water over time...though 6 weeks is pretty short. Maybe you had a bad batch of fluid or potentially if the fluid change was in humid temperatures or the fluid was left open exposed for some time...again pretty weak...but if present that water can turn to steam pretty easily which is what most people feel when they say their fluid "boiled". I have a hard time believing you exceeded the dry boiling point of 600 unless perhaps you were doing repeated 120-40 mph stops on track tires.

The more water saturated the fluid, the more important the wet boiling point is. The wet BP is usually over 200 degrees F less than the dry BP so it's paramount there is no water in there, which is why you should change it at least yearly.

If you want insurance, 660 is about is as good as it gets for us mortal with budgets.

The speeds were not high, but the braking was relentless. I've linked to a couple laps below. This went on for 40 minutes before the fluid finally boiled.

 

[MoreAgain]

What pads were you using? If stock, it's likely that you glazed the pads. Have you looked at them? My stockers were trashed after my first track day.

Mountain Pass Performance Track Pads with their BBK. Both still look pristine.

 

[MoreAgain]

BTDT with both versions of Motul fluid.

Go with Castrol SRF - it’s worth the extra $$. (speaking from personal experience)

Yes, sounds like the way to go. At this point I'm most likely going to do one of two things; 1) Nothing, just send it (most likely), or 2) if I mess with it at all, might as well do a full change to SRF.

Thanks all for the input.

 

[MountainPass]

Yes, sounds like the way to go. At this point I'm most likely going to do one of two things; 1) Nothing, just send it (most likely), or 2) if I mess with it at all, might as well do a full change to SRF.

Thanks all for the input.

You'll know when you got your rotors really hot, the hats will turn a purple-ish hue. It sounds like that morning session was unusually punishing on the brakes.

 

[FlyNavy01]

Nationwide shortage of Castrol SRF right now according to every website I've tried in the past 6 weeks. Hopefully it wasn't discontinued...

I just bought three 500ml bottles of Motul RBF 600 on amazon for $50 in the meantime.

 

[Rexpelagi]

To help with cooling I pulled the dust shields off all of the rotors to allow for more airflow - not sure if you are running them or if it will help. You could also add some ducting.

Since SRF seems to be basically unobtainium I started using Redline RL600 - for ~20min sessions at Road America this setup worked well with upgraded pads, no fade, but a 40min session is pretty long.

FWIW, with SRF in the car I boiled the fluid on stock pads within a lap - soft pedal into T1 at NCM Motorsports Park on Lap 2 of the 3rd session, and I was only running 2 laps per session before that. I don't blame the fluid - these cars can put a ton of heat into the system quickly.

 

[Davidss2]

Nationwide shortage of Castrol SRF right now according to every website I've tried in the past 6 weeks. Hopefully it wasn't discontinued...

The story I heard was that one of the component chemicals that is used in the production of SRF is unavailable worldwide. It didn't sound like it was a permanent issue. But I think it's been more like 6 months since production of SRF stopped. I remember a good while back that summit racing took it off their shelf and website and I was puzzled at the time as to why.

Time to hoard my last bottle! Good thing it's the racing off season!