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Depends on what you are using it for. What is it's dry boiling point? For track duty you want a higher dry boiling point since you change brake fluid often to keep the boiling point high. If you are interested in wet boiling point because you don't change your brake fluid annually then going with Castrol SRF will get you a 518 degree wet boiling point.
Other fluids will get you ~ 625 degree dry boiling points with wet boiling points similar to what your Prestone provides. For example Wilwood EXP 600 Plus brake fluid will get you Dry Boiling Point: 626 °F Wet Boiling Point: 417 °F. Ferodo Super Formula Racing Brake Fluid will get Dry Boiling point of 328 degrees C (622 degrees F) and Wet Boiling Point of 200 degrees C (392 degree F).
It all depends on what you are going to do and the cost you are willing to pay to get the performance required.
For example I use Ferodo Super Formula fluid and during track season I change it out before a track event if it has been in the brake system for over a month. Less than a month and I don't change it. That way I ensure I have close to the highest dry boiling point I can get. However, a 500 ml container of this fluid runs about $25 Vs whatever a container of Prestone costs. SRF is much higher in cost than the Ferodo fluid but it only has a 594 degree Dry Boiling Point.
Bill
Last edited by Bill Dearborn; 04-21-2020 at 12:49 PM.
Castrol SRF. Run it in my street C7 Z06, my TA2 Camaro and my ASA/GTA Monte Carlo (the last two are race cars and get flogged like a stolen mule, worse than a rented mule...). When we experienced the “great SRF shortage of 2019” we went with Motul 660 in my TA2 but we’d boil it pretty quick.
Even in my street Z06 I thought that maybe, just maybe, I’d be OK with the 660....as it’s what I used to run, before I started going w2w....nope....boiled it in a few laps at my home track. That was a waste of money. Put the SRF in and it’s golden. Just my experience. And that of many others. If you’re looking to skimp on the important things then this “sport / obsession” is not for you. <——- I know that this comes off as snarky / snobby and it is definitely NOT meant to be. I just see so many people wanting to skimp on things that really are not just a performance item but also a safety item. Soap box put away....
Last edited by Captain Buddha; 04-21-2020 at 01:57 PM.
Unless you plan to let your car sit for years without changing your brake fluid, don't waste your money on Castrol SRF. There are many options out there at much lower prices that will accomplish your goals. Focus on dry boiling point, which is the more important factor for the typical HPDE enthusiast. We recently wrote an article on this topic on our blog titled, "How to Choose Racing Brake Fluid".
We (Essex Parts) are a long-time forum sponsor and have thousands of bottles of AP Racing and Ferodo Racing brake fluid in stock, and we can ship the same day. We have many of hundreds of enthusiasts on this forum who we have helped with brakes, and nearly all of them are successfully running a fluid we supplied with our other brake components.
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Last edited by JRitt@essex; 04-23-2020 at 09:18 AM.
[QUOTE=JRitt@essex;1601377924]Unless you plan to let your car sit for years without changing your brake fluid, don't waste your money on Castrol SRF. There are many options out there at much lower prices that will accomplish your goals.Focus on dry boiling point, which is the more important factor for the typical HPDE enthusiast. We recently wrote an article on this topic on our blog titled, "How to Choose Racing Brake Fluid".
Excellent advice. I still can't wrap my head around the love for SRF. Why is wet boiling point even a thing in a tracked car? You're going to flush your fluid before the season at the very least regardless. Even Stoptech 600 and Motul 600 at $16 are rated better than $70 SRF dry . smh
I have RL-600 for now. I went to check price to see if I would still recommend it and read this bit:"Little known fact: all 600 and 660 fluids are made by Orthene, because they hold the patents. Only the bottles, stickers, and marketing materials are different between brands. That said, buy whichever temperature fluid suits you needs on price, rather than brand. Currently, Red Line's offering is least expensive. It will perform as well as Motul, Wilwood, or any of the others, because it is the same fluid."
I have RL-600 for now. I went to check price to see if I would still recommend it and read this bit:"Little known fact: all 600 and 660 fluids are made by Orthene, because they hold the patents. Only the bottles, stickers, and marketing materials are different between brands. That said, buy whichever temperature fluid suits you needs on price, rather than brand. Currently, Red Line's offering is least expensive. It will perform as well as Motul, Wilwood, or any of the others, because it is the same fluid."
That is really good to know! Kinda throws brand loyalty out the window on that one. I'm sure there are tons of other parts and fluids that share the same manufacture and we buy thinking it's a different or better product. That's where the educated consumer has a distinct advantage and can save money.
I use ATE Type 200 as well, but a minor correction: per their datasheet, wet boiling point is 388.4 degF.
I also use ATE fluid and it works great for the occasional track day and autocross events. I did like that it used to be available in two colors so you could know what to use next. The TYP200 and the Super Blue were the same DOT4 fluid except for the blue dye. But the gubbiment decided that brke fluid has to a very light yellow color.
Unless you plan to let your car sit for years without changing your brake fluid, don't waste your money on Castrol SRF. There are many options out there at much lower prices that will accomplish your goals.Focus on dry boiling point, which is the more important factor for the typical HPDE enthusiast. We recently wrote an article on this topic on our blog titled, "How to Choose Racing Brake Fluid".
Excellent advice. I still can't wrap my head around the love for SRF. Why is wet boiling point even a thing in a tracked car? You're going to flush your fluid before the season at the very least regardless. Even Stoptech 600 and Motul 600 at $16 are rated better than $70 SRF dry . smh
You can shake your head all you want...but there are those of us who have had less than stellar experience with other fluids...and Castrol SRF beats them all...at least in my applications. Regarding the wet boiling point and why it matters - my take - and just my take - once you've opened a bottle (and your master cylinder cap) you've introduced your fluid to moisture - ie - the humidity in the air...I've always gone with the brake fluid with the highest wet boiling point...and it has served me well. Again, feel free to shake your head....but when you are coming off the banking of the tri-oval at Daytona at 170-180 to hit Turn 1 and you get brake fade - soft-pedal....rethink your fluid....sure, make sure you've got maximum cooling, etc...but that's when you really start to see the "light!" Again, my experience. And this is in cars that are getting bled on a very regular basis...note that I said "bled" - not flushed - no need. You use very little of the SRF once it's in the system.
Unless you plan to let your car sit for years without changing your brake fluid, don't waste your money on Castrol SRF. There are many options out there at much lower prices that will accomplish your goals.Focus on dry boiling point, which is the more important factor for the typical HPDE enthusiast. We recently wrote an article on this topic on our blog titled, "How to Choose Racing Brake Fluid".
Excellent advice. I still can't wrap my head around the love for SRF. Why is wet boiling point even a thing in a tracked car? You're going to flush your fluid before the season at the very least regardless. Even Stoptech 600 and Motul 600 at $16 are rated better than $70 SRF dry . smh
Simple: With motul and the others, most track rats have to flush after every weekend or once a month etc. With SRF, it goes the entire year. So the cost argument is moot. its probably cheaper to run SRF in the end if you flush as necessary with non-SRF fluids. I myself run SRF becuase I don't boil it. I have boiled 600 and 660 Motul....
I'd love to see tested, hard facts on these scenarios. Side by side tests with actual temperatures, expansion rates, moisture content from being exposed to air, etc. When they post a dry boiling point, they can't flat out lie about it. It has to meet certain specs and tests. They would lose their asses if proven otherwise. I'd be more than happy to go by wet boiling point if the brake fluid was actually "wet" but it almost never is. I've seen the moisture content test on 1 year old, regular factory DOT 3/4 in a 2019 BMW master cylinder. It showed less than 1 percent. How could it sit around through hot, cold, rain, etc for a year and still read less than 1 percent? Point is, unless that fluid is directly exposed to significant moisture, you're never going to be dealing with a significant loss in wet boiling point. And you'll find the brake experts and engineers, people far more educated on the subject than us weekend warriors and wannbe racers, saying the same thing. Sure, you've used SRF and never had an issue, but that doesn't mean all of the other fluids would've necessarily failed. I think the fluids get blamed falsely most of the time there's a problem. Post hoc reasoning in most cases. I've had late session soft pedal with Motul 600. I had brake ducts, ti shims, race pads and T3 rotors. Upon inspection, the pads were melting into the caliper. ANY brake fluid is in trouble at that point regardless of the name on the bottle. How much is personal feeling vs objective proven analysis and facts?
Tross - I like your post...but like UrbanKnight above...if you've read my posts....same car...SAME DAY....same track....boiled factory fluid...full flush with Motul 660...boiled the fluid....brought it in...full flush with Castrol SRF....oh, and to even make it TOUGHER on the SRF....the earlier runs were in the morning here in Texas....cooler temps....so now, hotter temps with SRF....and guess what....yep....NO boil....so there, that's that car with me doing track duty....bone stock Z06 that I play around on track every now and then...
So you brought up "wannabe" racers...that's cute...some of us are actual racers...I'd say a good chunk...before I got into actual w2w I knew of and respected Castrol SRF...had experienced it myself...so...why do these professional race shops and professional race teams (many that have done dirt, Indy, prototypes / IMSA, World Challenge, Trans Am - with 20, 30, 40, 50+ years in the racing industry) continue to use SRF? Because it works, they've tried "a few things" over the years...and during the "great SRF shortage of 2019" we were forced to use sub-par fluid...it sucked, it really did. I can tell you as I was the one driving!! Sure, my Car Chief, Ed, he's 65, been around the racing world a bunch...has used pretty much every brake fluid known to racing...during the 2019 SRF shortage he made some calls to previous teams he's worked with that ran some great fluid from years ago (both a P-car specific series with P-spec race fluid and then another BMW-specific series with BMW-spec fluid)....nope, discontinued....oh well...you gotta try!
But y'all can keep on arguing and arguing about the merits of lesser fluid....and I'll keep on running Castrol SRF. There may be a reason why some folks (me included) can outbrake competitors in certain corners...sure, you've gotta manage brakes - they are all going to get hot...that's why you get as much cooling as you can to the system! Two to three cooling ducts/hoses to each front corner are the norm, especially with the cars I race. So, with beating on the brakes come other things...like cracking rotors...gotta say, finally found the right supplier with a non-asian foundry that heat treats their rotors...no more cracking every weekend!!
Since I like to flush the entire system a couple of days before track weekends I have been using a good dot 4 synthetic like valvoline or such and, quite frankly, there is always high humidity in the south. If you open the bottle, it is now getting contaminated with moisture quickly. Never had a problem in over 16 years of track. However, as of last year, I thought I might try the SRF in my two cars. I just bleed a little out of the caliper now and see how far it gets me. Full flush with SRF would get expensive quickly.
04-21-2020, 11:37 AM
What brake fluid do you all like ? DOT 4
