village idiot

ncstingray

Put the leftover fluid in a wine bottle and use a vacuum stopper. Just don’t serve up a round of SRF instead of your Chardonnay.

NSFW

Is SRF compatible with Merlot? Probably less chance of confusion that way.

redtopz

I use SRF and rarely bleed my brakes. Maybe once or twice a year? Here is an analysis a friend did on brake fluids, I don't think she would mind me sharing here. Her results show exactly what I have experienced, SRF doesn't go bad over time, in fact it seems to get better. I'm still using bottles that I've had for years. Also, it's likely that people are bleeding brakes too often for no real reason if you use SRF. Once or twice a year should be fine. I've never had a soft pedal with SRF so it's just preventative maintenance.

Brake fluid boiling point (in degrees Fahrenheit) was measured using the OTC 3890 device, at the middle to end of April, 2017. Thanks to Khurram who let me
borrow the OTC 3890 over the past couple of weeks. Successive numbers mean
the fluid was tested more than once.

MOTUL
Motul 600 (wet/dry boiling point--594/421):
1/2 full bottle, opened 1 wk before testing: 577
<1/2 bottle opened on 11/9/15: 496
the above 11/9/15 fluid in the Miata, tested from reservoir: 396/399
>2/3 bottle stored in truck, opened at least 3 yrs ago: 554
>2/3 bottle stored in garage, opened at least 3-5 yrs ago: 541, brown appearance

Motul 660 (wet/dry boiling point--617/399):
1/4 bottle, at least 2 yrs old: 424

CASTROL SRF (wet/dry boiling point--590/518)
Fresh bottle, just opened: 590
Fluid/bottle opened 7 wks prior to testing, driven on track for 273 miles
(1 event):
In bottle, 1/3 full: 601/603
In C5 brake reservoir: 604/599
In C5 clutch reservoir: 590
out of front passenger caliper: 574
Fluid/bottle opened 8/2016, 3/4 of a bottle: 606/597/601
Henry's bottle opened 11/2014: 601

ATE Gold:
Black E46, flushed 3/2017: 547
Blue E36 M3, flushed 11/2014: 464
Starlet, fluid 1 year old (I think): 486

BMW: DOT 4, 1/2 of 13oz bottle, opened a week prior to test: 532/529

Valvoline Synthetic DOT 3/4
in truck reservoir, flushed in ~11/2016: 504
fresh fluid: pending
in white M3: flushed 2/28/16 : 468
in green M3: flushed 2/2016 :464


Unknown type of fluid at least 4 yrs old, tested in reservoir: 394

My conclusion is that stored fluid, especially in a relatively full bottle,
can maintain a high boiling point, even over years!

village idiot

Wow that's awesome.

Dan H.

redtopz,
Thank you for sharing. This is supports what I've heard, its great to see data.

Dan

Quickshift_C5

Wow, that's impressive.

Tempted to move from Motul 600 to SRF before this season starts.

Poor-sha

IFL data. SRF was testing above it's rating out of an open bottle.

ncstingray

Quote from Castrol
"Castrol React SRF Racing is suitable for all disc and drum brake systems with the exception of those for which mineral oil is prescribed. It is miscible with all conventional fluids meeting US Federal Standards FMVSS 116 DOT 3 and DOT 4, ISO 4925 and current SAE J 1703 and J1704. However, mixing with conventional brake fluids will merely reduce the higher quality of Castrol React SRF Racing and therefore recommended that conventional brake fluids be drained from the system before flushing and re refilling. It is recommended that this fluid is changed every 18 months to maintain it's exceptionally high vapor lock performance."

How do you completely drain a brake system to not mix fluids?

Poor-sha

I don't think you need to 100% flush the system. Just suck what you can out of the MC reservoir, add new SRF, and bleed through the calipers.

Supercharged111

I bleed once a year and swear it's a waste. That said, I typically do about 6 NASA weekends per year and a couple practice days. 93 Camaro running C5 brakes with ducts, 260whp/3250# post race minimum. Pedal feels the same in October as it does in April.

SocalC5Z

Brake fluid used?

Supercharged111

Sorry, SRF. The Motul was not as durable. 2 weekends and the pedal felt fine, but fluid would come out dark.

apex26

Reading my log book, documenting the substantial improvement in switching to SRF, and prior advice concerning switching from my first instructor, a very bright aeronautical engineer who researches everything. He said Motul was developed for superbikes for better feel, because their race brakes are metal on metal, so designed to compress some..."so switch to SRF".

village idiot

None of that is true

BEZ06

I don't believe that's correct!!

Motul is an excellent brake fluid - just as non-compressible as any other top DOT racing brake fluid (or even street DOT 3).

He may have been talking about a DOT 5 silicone based fluid, but I don't think Motul makes a DOT 5.


You can read in the StopTech Technical White Paper bulletin about brake fluids, that virtually all the DOT 3, 4, and 5.1 fluids are formulated from glycol ethers and borate ester:

http://www.stoptech.com/technical-su...rs/brake-fluid

In there, the only fluid mentioned to have any siginificant compressibility at all is a silicone based DOT 5 fluid, which should never be used in any modern car. The compressibility is not something we want when braking hard on the track, and even for hard braking on the street, as the compressibility messes with the ABS:


Interestingly, read in the description of Castrol SRF below that it actually does have silicon ester in its formula, but silicon is an entirely different substance from silicone. I don't know if the silicon ester is used to entirely replace the borate ester in most DOT 4 and 5.1 brake fluids, or if it's in addition to borate ester:


Castrol info about SRF also says that to swap in SRF, just flush it in to replace your old fluid:

.

apex26

Thank you for the detailed clarification. This forum is great at debunking that which sounds plausible, from a credible source, but which is wrong or misleading. Mark Twain said "It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so".

village idiot

Like Abraham Lincoln warned, "just because it's on the internet doesn't mean it's true."

BaylorCorvette

Castrol SRF user here. I bleed once or twice a season and a complete flush once a season. I do an event about once per month, sometimes twice.

rabrooks

It sounds like the verdict is in.
1. SRF is the best.
2. The guys that "RACE", not hpde's say they bleed 2 to 3 times a season. I find that to be impressive.

So, I guess I'm spending more $$ than I have to. I have used SRF for the last 5 years or so. I have to replace my pads after 3 to 4 days on track. Since the tires have to come off to replace the pads, I go ahead and bleed most every time. Peace of mind, I guess. My wife helps me bleed and she feels helpful, and I appreciate it.