Castrol SRF brake fluid

[RACER X #99]

Anybody using Castrol SRF in their track car? And if so is it worth the very high cost?

RD

[Excaliber]

Wilwood 570 here. Just couldn't see the need to spend the extra money for more "exotic fluid" after I looked closely at several alternatives.
Ernie

[coyled]

Roger, I went from ford to motil and kept cooking the fluid, spongey pedal after a few hard sessions. I then went to castrol srf and have had no more of the spongey brake pedal. Its expensive, but it works great. I have done 4 weekends with it and have not bled the brakes again yet, the pedal is still rock hard. Scott.

[RACER X #99]

Scott,
That was the answer I was looking for. I ordered the Srf and I also just installed a brake cooling fan in the trunk to cool the calipers. I kept asking my racing buddies how come I never had brake problems before. Their answer was you are now driving much harder than you were before. Nothing like an ego boost to make you forget about the brake pedal going to the floor. I sure hope the Castrol and the new fan do the trick.

RD

[427sharpe]

Have you tried Valvoline Synthetic? Readily available and compatible with all major systems. We use it in HD trucks that really abuse brakes. I use to have some fade in my car when using DOT4, totally gone with switch to Valvoline type. A lot of the road racers at Hallett use it as well. Might be worth a try, as it is not very expensive. Available @ Pep Boys.

[RACER X #99]

Bob,
Almost all racers and manufacturers of racing brakes will tell you not to use synthetic brake fluid. Since I already bought the SRF and with the endorsement from Scott, that's what I will be using.
RD

[427sharpe]

Yes, I know that about the old line synthetics. Supposedly Valvoline has a 'new trick'.
"..is recommended for all ABS, hydraulic and drum braking and clutch systems requiring DOT3 and DOT4 fluids. It's premium, synthetic, low moisture formula provides superior anti-vapor lock protection. Has a high dry-boiling point, 513 degrees, that reduces the risk of fluid vaporization and possible brake failure. Exceeds all SAE and FMVSS brake specs. Surpasses all OE specs and WILL MIX WITH CONVENTIONAL FLUIDS. Wet Boiling point 333 F."
I added the last capitalization, as that is an important point as the old lines of synthetic brake fluids (DOT 5) would not mix with conventional fluids, nor did they meet oe specs. I found out about Valvoline Synthetic at the SAAC Mid America Nationals, where it is in common use among the raod racers that are on the SVRA circuit. I asked a few competitors about it because I had heard that DOT5 was not suggested. THIS IS NOT DOT5 TYPE FLUID. Before running it in my GT350 or the Cobra, I also called Tilton Tech and Wilwood, who both gave it the ok. As an aside, at the last NASCAR race here, it was being used in Mark Martins car when the had to bleed the brakes, so it is NASCAR ok too!
It has been in all my cars for over 2 years without difficulty, and has been in use at my old shops (4 retail service centers) for over a year, again, without any problems whatsoever.

[coyled]

Roger, I went to the castrol srf because of what Borris told me. He has tried them all and says it is by far the best. Also, when I baught it in phoenix, I did so from baer racing. Thay did their own independent tests and told me that the srf is the bast. It will melt pistons in the caliper before the fluid cooks. Once you use it, if you still have problems, its not the fluid. Scott

[John McMahon]

Scott,

So with the higher boiling point, it minimizes (or eliminates) the need to bleed your brakes after each event, right?

I guess it ends up paying for itself, if you don't have to bleed out a pint or two of the Wilswwod fluid or others after every event.

[RACER X #99]

Wilwood does not recommend using DOT 5 fluid in any racing applications. DOT 5 fluid is not hygroscopic, so as moisture enters the system, it is not absorbed by the fluid, and results in beads of moisture moving through the brake line, collecting in the calipers. It is not uncommon to have caliper temperatures exceed 200° F, and at 212° F, this collected moisture will boil causing vapor lock and system failure. Additionally, DOT 5 fluid is highly compressible due to aeration and foaming under normal braking conditions, providing a spongy brake feel. DOT 5 fluid is best suited for show car applications where its anti-corrosion and paint friendly characteristics are important.

From the Wilwood brake site. www.wilwood.com
RD

[Richard Hudgins]

Racer X,

Castrol SPF is certainly worth the money. It is standard on the JBL.

1. It has a very good boiling point.
2. It has a lower viscosity than other glycerin based fluids
3. It has better Hydroscopic numbers.
4. IT JUST WORKS BETTER!!!!!!!

5. All of the F1 boys use it as the carbon brakes get real hot and they need a fluid that will stand up to it.

However, I would still bleed the brakes prior to each session.
(I mean each session, not each weekend. Brakes are are something that I use to go fast, they must be perfect in any race car I drive.)

[Jamo]

Roger--good explanation re DOT 5. I think you hit the nail on the head re paint friendly--still think that's why it was even developed.

NOBODY uses it for autocrossing, and trust me, that's much harder on brakes than open track (unless it's a short course).

Yup--suspect your better driving is causing deeper and harder braking--way to go!

[Ikestaa]

Castrol SRF is the only thing we used on our Atlantic car. If it is good enough for one of those, I have a feeling it will work for a cobra.

[427sharpe]

Richard; out of curiosity, what are the numbers on the Castrol SRF? I am always looking for a good thing! Reading the posts, I think it was somehow lost that the Valvoline Synthetic IS NOT DOT 5, and is compatible with DOT 3 and 4, so it is safe for all brake and clutch systems. I like it due to it's higher boiling points.

[Greg Kulp]

Robert and all,

Here's a useful link courtesy of Bob Putnam. It provides dry/wet boiling points of some popular brake fluids and other information.

http://www.shotimes.com/SHO3brakefluid.html

By the way, I am using the Valvoline Synthetic in my Cobra and Mustang Cobra. I agree with Robert that it has some good properties, not hyper exepnsive, readily available, and is NOT Dot 5 "synthetic".

Greg

[Richard Hudgins]

427sharp,

sorry I did answer earlier. I just looked back at the thread today.

Castrol SRF Dry 590 Wet 518.

The problem is the stuff is just damn expensive. But works great.

Here are some comparative numbers.

Fluid DRY WET
Castrol LMA DOT 3/4 446 311
Ford Heavy Duty DOT 3 550 290
ATE Super Blue Racing 536 392
ATE TYP 200 536 392
Motul Racing 600 585 421
Castrol SRF 590 518
Performance Friction 550 284