So, the Manic Miata has blue brake fluid in the brake and clutch systems. I need to replace the clutch slave.
I've heard tell that blue fluid is now verboten. Is that true, or was that a rumor? Is there something compatible I can replace / supplement it with when I bleed the slave after replacing?
Thanks.
The blue is ate super blue. Same as regular ate fluid. Just dyed blue.
It's dyed blue so you can alternate between blue and clear each time you bleed the system. When the color out the bleeder changes, you know that corner is done.
It was pulled because it did not meet federal standards.
The federal standard for brake fluid is 49CFR pt 571.116 "motor vehicle brake fluids" (aka FMVSS 116)
within that is the following
"S5.1.14 Fluid color. Brake fluid and hydraulic system mineral oil shall be of the color indicated:
DOT 3, DOT 4, and DOT 5.1 non-SBBF—colorless to amber.
DOT 5 SBBF—purple.
Hydraulic system mineral oil—green."
means it is not legal for sale to be used on the road.
as far as I know that was the only reason it was pulled.
They specifically dyed it that way so that you could alternate colors and see when you got fresh fluid through, so as long as you are staying with a similar grade (DOT-4 in this case) you will be fine.
Additional references
Dusterbd13 wrote: The blue is ate super blue. Same as regular ate fluid. Just dyed blue.
So it looks like regular Type 200 is fine for the clutch. But, reading up on the Oil Guy, it sounds like I ought to replace the ATE blue stuff in the brake system and move to something else, as well.
fresh fluid in the brakes is never a bad idea...
I am unaware of any performance problems from using ATE super blue, it was actually pretty good stuff. But how old is the fluid in your car? Just remember that brake fluid pulls moisture from the air over time, which lowers its boiling point and also allows corrosion.
See also, why old british car brake systems can be problematic, they arent sealed very well, so they really need flushing every year. Noone does that though, so they get corrosion issues within the system.
I have used the ATE Blue and clear for years in my race car with no issues.
Rant/story time (cool story, bro! warning!):
I had my Chrysler minivan at the local dealer to have some warranty work done on it. While it was up there, I asked them to flush the brake fluid for me. I got a call back from the service advisor who informed me that my front brake pads were below 50%, so "bleeding it won't help."
Huh?
"Yeah, the pads are worn down, so as they wear more the fluid level will just keep going down!"
Uhhh.... Okay, but could you still flush them and put in fresh fluid?
"There's no point in doing that until you're ready to replace the pads and rotors."
I managed to stop myself from trying to explain hydroscopic fluids to the poor guy... I'll just do it next time I have the van on the lift..
I am in favor of brightly colored brake fluid. Any neon colors are acceptable. My brake fluid looks too similar to power steering fluid, and it would be easy to mix them up. Would also make spotting leaks that much easier.
In reply to WonkoTheSane:
"While it was up there, I asked them to flush the brake fluid for me."
Well, that was your first mistake... Dealer techs assume that if you are asking them to do anything, you don't know anything about cars and they can swindle you out of an expensive brake job.
I prefer DoT5 in my clutch hydraulics.
Dr. Hess wrote: I prefer DoT5 in my clutch hydraulics.
You do know that the rubber components aren't universally compatible between dot5 and dot 3/4 systems right?
You should be able to use dot5 where dot3 is supposed to be after a good cleaning, no promises though. Dot3 where dot5 was supposed to be usually ends badly, ask me how I know.
What advantage does dot5 have for clutch systems? I've seen mineral oil brake fluid used in clutch, and clutch style brake brake systems, but not dot5.
Don49 wrote: I have used the ATE Blue and clear for years in my race car with no issues.
I was just reading some fluid geeks on Bob The Oil Guy who were saying Type 200 wasn't up to track use.
Duke wrote:Don49 wrote: I have used the ATE Blue and clear for years in my race car with no issues.I was just reading some fluid geeks on Bob The Oil Guy who were saying Type 200 wasn't up to track use.
Like brake pads, it'll depend on the car. Some might put enough heat into the fluid to boil typ200, others may not.
That stuff got banned long enough ago that no matter how good it was, any fresh DOT3/4 fluid will be better now. Once you open the bottle glycol based fluids start picking up water out of the air and the boiling point drops accordingly. If you read the maintenance chart most cars tell you to flush it every year or two for that reason, so you don't boil the fluid and lose brakes the next time you find yourself on the downhill side of a mountain or whatever.
I've boiled ATE Blue, but it took some serious heat and some insufficient 2.5" ducts to do it. Had to go to Motul 660 and 3" ducts.
You can mix any DOT 3, 4 and 5.1 without ill effects. DOT 5 is a different beast.
Cool, thanks for all the info, folks.
I used to use Motul because it was easily available at the motorcycle store down the street, then I switched to ATE (half the price) when they started carrying that at the parts store. I've destroyed a lot of brakes on the track from too much heat, and I've never boiled the ATE while on track. I have had the pedal go soft when I parked the car after a session though, even with a cooldown lap and a couple trips around the paddock at 10 mph as well, so it looks like I'm probably going back to Motul.
AIUI, many OEM brake systems are designed so that the low fluid brake warning light does double duty as a pad wear sensor, on the assumption that you filled the system up when you replaced the pads and the worn pad requires a certain volume of extra fluid in the caliper. A lot of "normal" auto techs recommend not topping up or flushing fluid in the middle of pad lifetime for this reason.
You can boil it on track, but it takes a healthy V8 Miata and High Plains Raceway to do it 
HappyAndy wrote:Dr. Hess wrote: I prefer DoT5 in my clutch hydraulics.You do know that the rubber components aren't universally compatible between dot5 and dot 3/4 systems right? You should be able to use dot5 where dot3 is supposed to be after a good cleaning, no promises though. Dot3 where dot5 was supposed to be usually ends badly, ask me how I know. What advantage does dot5 have for clutch systems? I've seen mineral oil brake fluid used in clutch, and clutch style brake brake systems, but not dot5.
Clutch systems don't have much heat in them. Like any. In my experience, clutch hydraulics tend to pull in and keep more water in them than brake systems. That is, the DoT 3/4 fluids go bad, and go bad faster than brakes. I've had to rebuild maybe 2 or 3 clutch systems, MC and SC, to one brake MC on my RN Truck, for example. On my bike, I didn't check the rear brake fluid for like, I dunno, 15 years. Maybe longer. Yeah, I shoulda got to that. I started to have a problem and tore the system down completely, fully expecting both the MC and the caliper to be garbage. There was some light scuffing, otherwise, they looked great. That was DoT5 fluid. Since then, whenever I do a clutch system, I convert it to DoT5. You can get it super cheap on eBay in gallon MilSpec containers. It was used for the M1 Abrams brakes.
Oh, after the full system rebuild on my bike, the problem turned out to be a bad coupling copper washer at the flex line to solid line.
I used to alternate the colors, too. I liked it, but honestly you can TELL when clean brake fluid comes through. It looks completely clear and colorless in that little tube compared to the brown junk you get out.
There is probably a dye you can add to glycol and make your own?
The 911 with Pagid blacks (RS-14) can only go 14 minutes at Blackhawk with super clear. I upgraded to Brembo LCF 600 and I could go the full 25 but the pedal was getting pretty soft at the end.
I just put in Pagid RBF and now I can finally do full sessions with confidence in the brakes.
Ate super gold boiling point 536F
Brembo LCF 600 602F
Pagid RBF 622F
Ian F wrote: In reply to WonkoTheSane: "While it was up there, I asked them to flush the brake fluid for me." Well, that was your first mistake... Dealer techs assume that if you are asking them to do anything, you don't know anything about cars and they can swindle you out of an expensive brake job.
Yeah, I expecting the swindle, I just couldn't wrap my head around why they would try to talk me out of an hour or so of shop rate, when the fluid is clearly in need of replacement.
In reply to Lugnut:
That sounds like you need some ducts to get more airflow onto those calipers!
About the blue dye: I found it stained my brake fluid reservoir. Never had a hard time figuring out when there's fresh fluid coming though the bleeder, so for me the dye was just annoying without any real benefit.
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