Castrol SRF - no longer available??

[VFR750]

No one has Castrol SRF brake fluid in stock.

Summit no longer lists it
Many other say it’s out of stock.

Anyone else know what’s happened and where I can get some??

[911pcars]

Not too hard to get. Only 219,000 citations:

https://www.google.com/search?client=firefox-b-1-ab&ei=hJ04XYrxC9bz-gTBn67YCQ&q=castrol+srf&oq=castrol+srf&gs_l=psy-ab.3..0l10.2449.4911..5266...0.0..0.715.2851.4j3j0 j1j1j1j1......0....1..gws-wiz.......0i71j35i39j0i131j0i67j0i10.kwzsnNilplc&ved=0ahUKEwiKw4mMks7jAhXWuZ4KHcGPC5sQ4dUDCAo&uact=5

[VFR750]

And when I try to place an order at the usual places I get “out of stock”

[spyerx]

Try Brembo HTC64T or Endless RF650

These are both high temp racing fluids. I prefer Brembo.

[911pcars]

Originally Posted by VFR750

And when I try to place an order at the usual places I get “out of stock”

Unless you're shopping price or you only buy from your favorite Porsche parts house, you're not trying hard enough.

The first link I selected from that google search page was at Amazon. They have 13 liters in stock with about 15 independent backup sources ready to ship.

Buy it but don't waste it by pressure bleeding it all out.

Sherwood

[Bill Verburg]

Here's a list, in order best to next etc, of the best b/f out there


For Mikes application where his brakes are highly stressed SRF is the way to go

for mine which are not stressed much, RBF 660

[911pcars]

I assume Mr. Verburg's BF chart, column 5 describes the Wet boiling temp. specs. That is, the boiling point of that BF with a given % of moisture.

That is the more important spec to understand since all BF attracts moisture once out of the can.

Sherwood

[VFR750]

Yes. Wet boiling point is the driver. SRF is the best

I have looked at my favorite sites for SRF. (Pelican does not sell it)
Pegasus, summit, jegs, og racing. They don’t have it in stock and jegs says it will ship from castrol in October. Hence my op

[Chilling in VT]

I bought a quart out at the little shop at the end of the garages when we were out at Watkins Glen last month. They had quite a few bottles on the shelf. You might want to give them a ring.

[naro914]

I just ran across this thread - not sure if you guys were able to get the SRF when it became available again? or if you still need any? we have 8 bottles left at the moment.

https://naroescapemotorsports.com/product/castrol-react-srf-brake-fluid/

[911pcars]

Seems to be available:

https://www.google.com/search?safe=active&sxsrf=ACYBGNRU6LnteR5BF3fbm5LLKRANmba8ng%3A1580339 351476&source=hp&ei=lxAyXpedGuyx0PEPy_ijuA4&q=castrol+srf+brake+fluid&oq=castrol+srf+brake+fluid&gs_l=psy-ab.3..0l9j0i22i30.2375.7279..7500...2.0..0.195.181 6.22j1....2..0....1..gws-wiz.....10..35i362i39j0i131j35i39j0i10.F6sgWIx1lYU&ved=0ahUKEwjXxKrt9qnnAhXsGDQIHUv8COcQ4dUDCAc&uact=5

[Solamar]

Just for fun I looked up Napa DOT 3 brake fluid wet boil, 284*f.

Well below the bottom of the list above...

[naro914]

Originally Posted by 911pcars

Seems to be available:

https://www.google.com/search?safe=active&sxsrf=ACYBGNRU6LnteR5BF3fbm5LLKRANmba8ng%3A1580339 351476&source=hp&ei=lxAyXpedGuyx0PEPy_ijuA4&q=castrol+srf+brake+fluid&oq=castrol+srf+brake+fluid&gs_l=psy-ab.3..0l9j0i22i30.2375.7279..7500...2.0..0.195.181 6.22j1....2..0....1..gws-wiz.....10..35i362i39j0i131j35i39j0i10.F6sgWIx1lYU&ved=0ahUKEwjXxKrt9qnnAhXsGDQIHUv8COcQ4dUDCAc&uact=5

But go to most and they say “backordered” or not available.
Summit, Pegasus, OGRacing, Discovery are all out. We have a local Nascar huge supplier that keeps a few cases always available for us.
I just ordered another 2 cases today.

Customer of ours ordered from Amazon when we were out in October...it never showed up.

[Driven97]

Wow ATE Typ200 (used to be able to get in blue also for easy bleeding) is 536°/388° and also wouldn't make that list.

Quick question, do these hyper fluids have decent life or do you have to change / re-bleed often?

[VFR750]

Depends on what you are doing. Street? Don’t bother with the high end stuff. Trackday? I bleed after every event and flush at least twice a season. Racing? Probably flush after each race weekend would be my guess.

[Driven97]

I guess I'm asking for those who use the car on the street but do 1 or 2 track days a year. Do the fancy fluids make poor street fluids for any reason.

[Jonny042]

Originally Posted by Driven97

I guess I'm asking for those who use the car on the street but do 1 or 2 track days a year. Do the fancy fluids make poor street fluids for any reason.

Unless you're brakes are marginal for the application (not likely if you ask me, on a 911, the brakes are huge) the maintenance of the fluid is more important than the brand, assuming it's half decent to begin with.

When I was racing IT, which required stock brakes, I used Wilwood fluid. I changed it a couple times a year. For the odd track day you'd probably be wise to freshen in the spring.

Here's a little quote from Wilwood. I found the point about the DOT 5 fluid interesting.

Due to the extreme operating temperatures of a high-performance brake system, standard off-the-shelf brake fluids are not recommended. Of critical importance in determining a fluids ability to handle high temperature applications is the Dry Boiling Point and compressibility.

The Dry Boiling Point is the temperature at which a brake fluid will boil in its virgin non-contaminated state. The highest temperature Dry Boiling Point available in a DOT 3 fluid is 572 degrees F.

The Wet Boiling Point is the temperature a brake fluid will boil after it has been fully saturated with moisture. The DOT 3 requirement for wet boiling point is a minimum temperature of 284 degrees F.

There are many ways for moisture to enter your brake system. Condensation from regular use, washing the vehicle and humidity are the most common, with little hope of prevention. Glycol based DOT 3 & 4 fluids are hygroscopic; they absorb brake system moisture, and over time the boiling point is gradually reduced.

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 degrees F, and at 212 degrees 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.

Whenever you add fresh fluid to your existing system (never mix fluids of different DOT classifications), it immediately becomes contaminated, lowering the boiling point of the new fluid. For maximum performance, start with the highest Dry Boiling Point available (try Wilwood Hi-Temp 570 Racing Brake Fluid), flush the system completely, and flush it regularly, especially after severe temperatures have been experienced.

Matt, I really enjoyed your blog about Autocrossing the Carrera, thanks so much for documenting that - I ended up following your example and widening the front Euromeisters on my car to 8" to suit 225 front tires. The car is FAST! The re-geared transmission is the biggest contributing factor. I do need to address the damper situation when I have time. Currently running 21/28 TB's and Eibach sways and HD front/Sport Bilsteins. Here's a quick vid. Room for lots of improvement, this year will bring a TBD diff and a quick steering rack and maybe a revalve of the shocks, and maybe 29mm rear TB's...... seems a little soft.



Have you documented the track-day experience at all on the blog? I've thought of doing some track days in the Rot Rod and would love to hear how you've made out.

[VFR750]

Originally Posted by Driven97

I guess I'm asking for those who use the car on the street but do 1 or 2 track days a year. Do the fancy fluids make poor street fluids for any reason.

The higher temperature capable fluids DOT4 are just fine for the street. I use them year round.

Some, fluid like the Motul 600 seem to be a little bit mushy, even when new. This makes the pedal feels softer than a stock fluid.

My observation is SRF seems to be less compressible.

Thats probably the only trade off, depending on the fluid.

[911pcars]

Just a reminder. Any liquid in an enclosed system cannot be compressed unless air is introduced or caused by heat hot enough to boil (vaporize) it.

Caveat (CMA):
https://www.physlink.com/education/askexperts/ae15.cfm

Sherwood

[WP0ZZZ]

Originally Posted by 911pcars

Just a reminder. Any liquid in an enclosed system cannot be compressed unless air is introduced or caused by heat hot enough to boil (vaporize) it.

Caveat (CMA):
https://www.physlink.com/education/askexperts/ae15.cfm

Sherwood

The bulk modulus of a liquid is the physical property that tells us how much a liquid will compress when subjected to pressure:

https://en.wikipedia.org/wiki/Bulk_modulus