LV Brake Fluid

[StigsBaldBrother]

I didn't know there was such a thing as low viscosity brake fluid. Is it required just for low temperatures or does it affect ABS performance?

I didn't have any thermal issues at Sebring, but I don't have caliper temperatures either to know if I'll be needing a higher temperature brake fluid in the summer. The only LV fluid, other than Ford's, that I could find is made by Pentosin. Anybody have experience with LV or with Pentosin?

 

[StigsBaldBrother]

Just wanted to bring this topic up again. Anyone have any input?

 

[ArizonaBOSS]

Sorry, not been exposed to this particular topic before. Is there a specific brand or part number you're curious about? I wasn't aware of any particular "low viscosity" requirement. Brake Fluid is almost the consistency of water as-is...that's pretty low viscosity

 

[StigsBaldBrother]

The viscosity of hydraulic fluid varies significantly with temperature over the temperature extremes that Ford has to design the Mustang to work within.

A few quotes from the Stoptech article on brake fluid (http://stoptech.com/technical-support/technical-white-papers/brake-fluid):

"Boiling point and viscosity are the most relevant properties to most consumers, including high performance customers. Viscosity is an important factor for proper operation of ABS and Active Handling Control systems on modern vehicles since in most cases the pressure and volume of fluid transferred is not measured. Instead, flow through a valve with a given orifice size over time are the control mechanism, so fluid maximum viscosity is a key characteristic."

"DOT 4 is the grade applicable to most race engineered brake fluid in the world today, especially with regard to viscosity limit. Note that although the DOT 4 designation has a minimum dry and wet boiling point, a DOT 4 racing brake fluid may have a dry boiling point over 600F. Its viscosity is challenged, however, to be under the viscosity limit of 1,800 mm2/sec. Some claimed racing brake fluids exceed this important limit. Caution should be exercised if these fluids are used in race cars with ABS systems. "

Although I couldn't find this chart in english, the first two rows are the viscosity of the fluid at the temperature extremes. You can see the differences between the racing brake fluid, DOT 4 and DOT 4 LV.

Now, I understand that I'm not going to be racing in -40 degree Celsius weather, especially in Florida, but there is a slight difference at +40 degree Celsius. Will it affect the ABS and Stability Control? Probably not. But that's the question I was looking to answer.

 

[ArizonaBOSS]

I suppose I can't answer that question. All I can offer is that I beat the snot out of Brembo LCF and Brembo HTC-64T in ambient temperatures up to 100*F with zero noticeable impact on braking system performance, including ABS. I would assume Castrol SRF offers similar performance.
You may save yourself a lot of time on this particular inquiry by going to one of those fluids.

 

[Fabman]

"Endless fluid" is said to be of a higher viscosity to give the pedal a firmer feel.
That's what Kevin uses in his track Mustang.
It was originally made for F1 Cars so it's a little on the pricey side, but supposed to be killer..
I just have Wilwood 600 in mine cause I'm a poor boy.
http://www.endless-brake.info/index.php/products/brake-fluid

 

[OPMustang Tim]

All I run is Pentosin LV, its good to 509+F so depending on your plans you can upgrade it. Lot of mis-information on how good the stock fluid performs. It just needs to be fresh. If you boil it you are putting too much heat into the caliper. High Temp fluids are the standard because it covers under performing contaminated fluid properties. The official statement is always run racing fluid, my issue with that is if you run a street car and or use any of the modes of the Nanny system you will change the characteristics of the systems operations. Will you notice? Who knows. SRF is non-existent currently unless someone has a stash due to an importation/labeling issue. We added Endless, Brembo HTC64, and Motul 600 to support the lack of SRF. Endless maintains High Vis. at elevated temps, no personal experience on how it works with Fords System. It also has a high wet BP. HTC64 was in a lot of INDY 500 cars this year but how that relates to a dual purpose Mustang I can't say. Logic has become nearly non-existent for brake fluid on the internet just like "What Oil Should I run" The process of flushing brake fluid is what helps the most, higher temp fluid just has a larger temperature delta to cover before it reaches a dangerously Low BP. The rate of change is something no one talks about or trends. You can use a resistance type tester to trend moisture content in fluid yourself. Running OEM fluid, it's so cheap you can just make it part of a regular track prep with no real cost impact. On a race car with a race braking system running at that level you will need a higher temp fluid, but I can assure you that fluid is a regular part of event prep at the pro level. Too much at stake to go to a $30K race and not change $100 fluid

 

[VoodooBoss]

Member YoPauly used Endless in his Boss with good results. It worked well in that system.

 

[StigsBaldBrother]

Thanks guys. I'm sure that I won't notice the difference. I'll continue to run either Pentosin LV or Motorcraft.