[EvaaWilli]

Thanks for the useful information.

[TrackClub]

Originally Posted by LESS1

While not exactly the same as the conditions mentioned by Sam and rs4eva. I have experienced what I will call a long pedal in my SS 1LE with RBF600 on OEM pads. What I mean is this, light pedal pressure/feel with exceptionally long pedal travel to get a good bite. Fluid and pads were changed a few days before the event and pads were properly bedded. Also, I did not have any fluid leaks or other issues.

This happened on two extended runs over 30 mins session during an open track event last year at Summit Point Shenandoah. Ambient temps were over 100 deg and as far as I can tell I was boiling the RBF 600 fluid. To compensate I cut my session to ~20 mins and had no further issues.

After this experience, I promptly switched to SRF with OEM pads and have not had this "long pedal" issue in 8 plus days on track in both summer as well as winter temps. By the way, I am changing the OEM brake lines before my next rack day. Ordered some nice Spiegler stainless steel lines a few days ago.

A classic case of boiling the fluid

I think we should pause before arriving at conclusions of "the same as" - as frankly we would need to compare many details to be remotely factual.

The closest incident in "the same as" category regarding the OP is the Supra. Same event, same day, same RBF600 fluid, same corner and seemingly the same result of no pedal in a very sudden fashion. At least that's as "the same as" based on my observation. Yet clearly, many details are missing to make it an objective conclusion.

Btw, I recall reading some posts previously about folks having some sort of difficulties with RBF600 if my memory serves me right. Some fluids have different viscosities and other properties (beyond temp ratings) which may, or may not be liked by some internal systems. This is a guess only, but Tadge eludes to it in his response, albeit in a very generic fashion.
It is also a mystery to me what he means by "DOT4 for track vs race fluids like SRF and RBF". Is he suggesting that some DOT4 fluids should not be used? Again, i find his statement rather incomplete and hence confusing.

Clearly, cooking RBF600 with stock pads even during longer session throws big question marks for me.
Until last season, when i switched to SRF, i had used Willwood 570 Racing fluid. It is an old and proven DOT3 formula (yes, a racing DOT3 fluid!), with lower temp ratings than RBF600, yet i had no issues with it. Except for ST43s which cooked it in just a couple of laps (no surprise). As a matter of fact, i had used it on my previous cars, including several 45min sprint w2w races with top dog DSUNO pads in my C5Z (see note) However, unlike SRF i had to bleed it every 3-4 track days.

Note: not all race pads deliver the same levels of torque. As one previous post in this thread demonstrates, some manufacturers don't necessarily believe more torque is better, or required to make a pad a race category. Majority (if not all) *warn* against mismatching pads vs tires. Yet tons of folks put incredibly high torque pads on their street cars, with little or no mods to their street braking systems. Moreover, some folks also change factory brake bias by putting different pads F vs R. Etc.

Bottom line: let's keep examples coming for the benefit of our community. But resist the urge to draw definite conclusions without detailed data. Or being overly critical of the posters, who volunteer their experiences.
C7 experiences aside, there seems only 1 Camaro who reported "loss of brakes" thus far? Of course i had lost brakes as well in my 1LE, but clearly it was due to a complete mismatch between high torque pads and inadequate brake fluid. Cheers!

[TrackClub]

One more note: i would categorize the amount of fluid on calipers in the pix above is normal.

Lastly, i would NEVER take my car to a dealer to have brakes bled, as they probably never do it and probably would assign the task to a jr tech, who probably would have zero idea about it.

[Boost Creep]

...or worse, introduce air to the system.


I've found if you want something done right, do it yourself.

[TrackClub]

Originally Posted by Boost Creep

...or worse, introduce air to the system.


I've found if you want something done right, do it yourself.

That's exactly the issue i was thinking about!

[m3bs]

I use a syringe and a short length of tiny tubing to suck the residual fluid from the bleeder screws. No sign of “leakage” after abusing them for two days at Road Atlanta last weekend. I was really impressed with the performance with stock pads, RBF660 fluid. Rotors still look like new.

[TrackClub]

Originally Posted by m3bs

I use a syringe and a short length of tiny tubing to suck the residual fluid from the bleeder screws. No sign of “leakage” after abusing them for two days at Road Atlanta last weekend. I was really impressed with the performance with stock pads, RBF660 fluid. Rotors still look like new.

I've also been impressed with a similar combo: stock Ferodos and SRF. My calipers still look brand new after 3 years. Rotors last very long. I think SRF or RBF660 are a good match for our cars with advanced drivers. Anything less could become problematic, especially with high torque pads. Imo.

[LESS1]

Originally Posted by TrackClub

A classic case of boiling the fluid

I think we should pause before arriving at conclusions of "the same as" - as frankly we would need to compare many details to be remotely factual.

The closest incident in "the same as" category regarding the OP is the Supra. Same event, same day, same RBF600 fluid, same corner and seemingly the same result of no pedal in a very sudden fashion. At least that's as "the same as" based on my observation. Yet clearly, many details are missing to make it an objective conclusion.

Btw, I recall reading some posts previously about folks having some sort of difficulties with RBF600 if my memory serves me right. Some fluids have different viscosities and other properties (beyond temp ratings) which may, or may not be liked by some internal systems. This is a guess only, but Tadge eludes to it in his response, albeit in a very generic fashion.
It is also a mystery to me what he means by "DOT4 for track vs race fluids like SRF and RBF". Is he suggesting that some DOT4 fluids should not be used? Again, i find his statement rather incomplete and hence confusing.

Clearly, cooking RBF600 with stock pads even during longer session throws big question marks for me.
Until last season, when i switched to SRF, i had used Willwood 570 Racing fluid. It is an old and proven DOT3 formula (yes, a racing DOT3 fluid!), with lower temp ratings than RBF600, yet i had no issues with it. Except for ST43s which cooked it in just a couple of laps (no surprise). As a matter of fact, i had used it on my previous cars, including several 45min sprint w2w races with top dog DSUNO pads in my C5Z (see note) However, unlike SRF i had to bleed it every 3-4 track days.

Note: not all race pads deliver the same levels of torque. As one previous post in this thread demonstrates, some manufacturers don't necessarily believe more torque is better, or required to make a pad a race category. Majority (if not all) *warn* against mismatching pads vs tires. Yet tons of folks put incredibly high torque pads on their street cars, with little or no mods to their street braking systems. Moreover, some folks also change factory brake bias by putting different pads F vs R. Etc.

Bottom line: let's keep examples coming for the benefit of our community. But resist the urge to draw definite conclusions without detailed data. Or being overly critical of the posters, who volunteer their experiences.
C7 experiences aside, there seems only 1 Camaro who reported "loss of brakes" thus far? Of course i had lost brakes as well in my 1LE, but clearly it was due to a complete mismatch between high torque pads and inadequate brake fluid. Cheers!

In my case I didn't actually lose the brakes... just needed to use more pedal travel to get bite. So not the same as others described. How accurate those descriptions are is as you mentioned unknown at this point. Also in regards to RBF 600 issues. After my experience, I began looking for a replacement brake fluid. During my research I found this url... http://www.torquebrakefluid.com/comp...ke_fluids.html notice how RFB 600 has a very low "wet" boiling point. This is critical if you don't change brake fluid very often as it will absorb moisture very quickly. And really makes the "dry boiling point irrelevant for some of us, unless as I mentioned you are changing brake fluid very often.

[TrackClub]

Originally Posted by LESS1

In my case I didn't actually lose the brakes... just needed to use more pedal travel to get bite. So not the same as others described. How accurate those descriptions are is as you mentioned unknown at this point. Also in regards to RBF 600 issues. After my experience, I began looking for a replacement brake fluid. During my research I found this url... http://www.torquebrakefluid.com/comp...ke_fluids.html notice how RFB 600 has a very low "wet" boiling point. This is critical if you don't change brake fluid very often as it will absorb moisture very quickly. And really makes the "dry boiling point irrelevant for some of us, unless as I mentioned you are changing brake fluid very often.

Thanks for posting this link. Ive seen it before but could not find it. As i had suggested before, there is more than just temp specs to consider when selecting a fluid and this link speaks to it very well. All test parms play a role.
There was a good article on this from Willwood, but i cant find it anywhere either.

You also make a very good point about the wet vs dry boiling points. In addition to it, DOT4 absorbs moisture much faster than DOT3. That's why it is unsuitable for long term use vs regular OEM fluids. Of course i am not suggesting using an OEM for track, but that's something to keep in mind.

Looking at the posted tests, looks like SRF is worth every penny. Given that it lasts a whole season with just a mid season bleeding, it is my choice anyway.
It seems very stable and when we bled it last year after about 10 track days, it came out looking hardly any different than new. This was my experience anyway, with stock pads, so nobody should take it as a scientific proof of anything and make their own educated choices. Albeit a very fast and a very prolific top driver here (Provoste) expressed a very similar experience on his car (with DTC60 pads).

Lastly, while BRF600 may work for some, it appears that it won't for others. Clearly you had managed to pass its limits yourself even with stock pads (!!!), the Supra driver boiled it suddenly and catastrophically and Sam may have run it as well (with very aggressive pads) albeit it is not clear what exact fluid he called "600", or what really happened.

Cheers!

[LESS1]

Originally Posted by TrackClub

You also make a very good point about the wet vs dry boiling points. In addition to it, DOT4 absorbs moisture much faster than DOT3. That's why it is unsuitable for long term use vs regular OEM fluids. Of course i am not suggesting using an OEM for track, but that's something to keep in mind.

Cheers!

The term you are referring to is hygroscopic. And actually DOT3 is normally more prone to absorbing h2o than DOT4. This is due to the type of Glycols used to produce DOT3 and DOT4.

[TrackClub]

Originally Posted by LESS1

The term you are referring to is hygroscopic. And actually DOT3 is normally more prone to absorbing h2o than DOT4. This is due to the type of Glycols used to produce DOT3 and DOT4.

Yep that's the term indeed. As far as i know, the higher the dry point the more hygroscopic the fluid is - as a rule of thumb. Perhaps that's why no OEMs put DOT4 as a factory fill. Just musings on my part here cheers!

[RUQWIKR]

Originally Posted by TrackClub

Yep that's the term indeed. As far as i know, the higher the dry point the more hygroscopic the fluid is - as a rule of thumb. Perhaps that's why no OEMs put DOT4 as a factory fill. Just musings on my part here cheers!

Some of the GM plants do - haven't always - but do now. For example, look at Page 250 of the 2019 Corvette owner's manual. The 2019 Corvette Track Prep Guide still says to change to a Dot 4 with dry boiling point >590F.

https://my.chevrolet.com/content/dam...ers-manual.pdf

The brake/clutch master cylinder
reservoir is filled with GM approved
DOT 4 brake fluid as indicated on
the reservoir cap.

[m3bs]

European makes have always specified DOT4, but they also call for periodic fluid changes every 2 or 3 years. In deference to lazy American owners, the domestics call for DOT3 and don’t mandate fluid changes. Supposedly the real world performance of the DOT3 degrades less over time. I’ve read a number of technical papers on the subject.

It might be overkill, but I push at least 1/2 a liter through my brake system before every track weekend. The plan has served me well for 30 years now. I also have a lot of used brake fluid to get rid of somehow......

[TrackClub]

Originally Posted by RUQWIKR

Some of the GM plants do - haven't always - but do now. For example, look at Page 250 of the 2019 Corvette owner's manual. The 2019 Corvette Track Prep Guide still says to change to a Dot 4 with dry boiling point >590F.

https://my.chevrolet.com/content/dam...ers-manual.pdf

The brake/clutch master cylinder
reservoir is filled with GM approved
DOT 4 brake fluid as indicated on
the reservoir cap.

Good ol' GM. I knew the Vette was special Good to know and thanks for pointing this out to me. Cheers!