Using higher quality brake fluid vs using cheap but changing more often

[rice_classic]

Originally Posted by celica73

Does not compute.

The biggest evil for brake fluid is moisture. Where do you think the moisture gets in? It's not at the caliper, that's sealed. The moisture gets in at the reservoir cap. Consider everything in the reservoir contaminated after 2-3 months.

Only if your reservoir cap is broken. Brake fluid in a daily driver situation degrades very little over the course of 2-3 years (or longer). What leads you to believe that the fluid in the reservoir is bad in 3 months? In properly functioning brake system the thought that your reservoir fluid is contaminated in 2-3 months is frankly ridiculous.

While brake fluid's biggest enemy (inherently) is moisture because it's naturally hygroscopic, in our application the leading cause of degradation is not moisture but heat. Thus, the fluid in and close to the caliper will degrade quite rapidly in our application while the fluid further up the line, and also in the reservoir is essentially "unscathed".

CSG Mike brings up a good point. Some cars are "under-braked" like the S2k and don't handle the heat quite as a well. The S2k is an example and so is my ITA CRX (with 9.5" rotors) but after some good brake ducting I went from bleeding my brakes after every other session to once every few race weekends, that's a massive improvement. The S2k guys have seen this as well.

Any of us track junkies can reduce how fast the fluid in the calipers degrades by adding ducting. You can also get titanium backing plates that fit in between your brake pad and your caliper which drastically reduces how much heat is transferred from the pad into the caliper.

[sw20kosh]

Originally Posted by CSG Mike

We recommend replacing your fluid whenever it feels sub-par.

Yeah makes sense and is what I generally do. Unfortunately it is a subjective way of doing it. "feels sub-par" is hard to judge in car you daily drive and thus may not feel it getting worse slowly over time.

[Hanakuso]

Originally Posted by sw20kosh

Is this fact? Should I be replacing my fluid every 3 months regardless of track duty?

I don't understand the science but I do know some cars these days say they never need to replace the brake fluid or coolant. Sounds absurd and I wouldn't really want a 200k mile car with the same brake fluid or coolant.

[CSG Mike]

Originally Posted by sw20kosh

Yeah makes sense and is what I generally do. Unfortunately it is a subjective way of doing it. "feels sub-par" is hard to judge in car you daily drive and thus may not feel it getting worse slowly over time.

Ah, I apologize. I'm a very "feel" oriented driver (as opposed to visual); I drive based on what I feel is fastest, and use data to validate/invalidate my "feel". Visual drivers pick out braking point markers, turn in markers, etc., which I don't do at all.

This carries over to my subjective feel of the brake pedal, which, I realize, doesn't work for everyone.

If the top of the pedal has a "dead zone" that takes very little pressure to press on the brake pedal, then I would recommend bleeding. The brake pedal should have a linear increase in pedal pressure as you go down, not a sudden jump. If the fluid in the brake reservoir looks dark and/or opaque, I would also recommend bleeding.

Please keep in mind that I do indeed DD the cars that I track; I'm currently DD'ing the shop BRZ while the S2k is getting some work done (thank you CSG owners...).

[MyRx]

Great points made here. Everything I've been taught you guys are explaining well. I'm using blue Ate and I've just been bleeding little by little since replaced and SS lines (~2k miles ago). After slight bleeding and slight refill, pedal does feel better (subconsciously perhaps). But I have to use up a 2nd bottle of Ate. I like the blue reservoir, my car is blue.

[Scooby South]

Motul Without question... and it doesn't get Old .I have used it pretty religiously for the last 10 years or so.. I have a instrument that measures moisture in the Brake fluid.. and check mine pretty regularly.. NO ISSUES..

For Reference:

[CSG Mike]

Project Mu G-Four 635F dry boiling point, 430F wet boiling point.

[/QUOTE]


We stock both Motul (Both RBF600 and RBF660) and Project Mu, as well as AP Racing and Ferodo.

[Scooby South]

Castrol SRF is the absolute Best.. but that stuff is like $70 per liter.. ATE Blue is about $17 per Liter... Motul is $18 for the 600 and $29 for the 660..
SRF and the 660 is mainly for endurance racing like the ROLEX 24..

for more normal track day stuff.. Motul 5.1 or RBF 600 should be fine..

Bill

[CSG Mike]

Originally Posted by Scooby South

Castrol SRF is the absolute Best.. but that stuff is like $70 per liter.. ATE Blue is about $17 per Liter... Motul is $18 for the 600 and $29 for the 660..
SRF and the 660 is mainly for endurance racing like the ROLEX 24..

for more normal track day stuff.. Motul 5.1 or RBF 600 should be fine..

Bill

You're thinking a different SRF from the one on that picture... a certain silicon based fluid that we'd love to use if we could...

[Black Tire]

Originally Posted by Scooby South

Motul Without question... and it doesn't get Old .I have used it pretty religiously for the last 10 years or so.. I have a instrument that measures moisture in the Brake fluid.. and check mine pretty regularly.. NO ISSUES..

For Reference:

The information on AP600 is incorrect or out of date. This is a DOT4 fluid with a dry boiling point of 594°F and a wet boiling point of 399°F. Being a DOT4 fluid it is compatible with all other DOT4 fluids. Read the fine print on the label from a fresh bottle:

[Scooby South]

^^^^ thanks.. got the chart from a Racing supply store..

Bill

[celica73]

Originally Posted by sw20kosh

Is this fact? Should I be replacing my fluid every 3 months regardless of track duty?

I never said that. Around town you don't need a dry boiling point of 600 degrees. Other than causing the lines to rust from the inside out, "wet fluid" should be just fine.

I also agree in principle with rice_classic, the fluid should be fine for as long as it's in a track car (simply because the fluid generally does get flushed out regularly). The club I run events with mandates 3 month or less for fluid. It's up to you to actually adhere to that. The rule is probably in place because 1/2 of the people that show up to a track event will say "I don't know" when asked how fresh their fluid is.

Scooby South has the right tool for the job, but most folks don't actually know the quality of the fluid.


Now, my one brake bleeding tip for the day (for those that don't already do this). Never push old fluid back into the system. Crack a bleeder screw any time you compress the caliper pistons. All the burned nasty stuff will go to the waste jug where it belongs.

[OrbitalEllipses]

Originally Posted by celica73

Now, my one brake bleeding tip for the day (for those that don't already do this). Never push old fluid back into the system. Crack a bleeder screw any time you compress the caliper pistons. All the burned nasty stuff will go to the waste jug where it belongs.

That's a good tip, didn't even realize that you're pushing old fluid back into the system when you're doing a pad change and compress the pistons. Obviously you do, I just hadn't considered it. Thanks!

[N_I_N]

3 questions:

1. Are there any DOWNSIDES to running any of these high performance fluids other than costs?

I am a newbie on mechanical things, but I'm pretty mechanically inclined. I know that sounds like I'm cancelling out the first statement with the second, but what I mean is; as long as I have directions, I'm pretty good at following something and putting 2+2 together if I run into an unknown. So question 2...

2. Has anyone seen a really good tutorial for bleeding brakes online?

3. How much fluid would one need to completely flush the FR-S system?