I flushed my brake fluid about 2.7 weeks ago with ATE Type 200 (Super Blue) and I have some leftover. It's been sealed in the same tin can it came in. Now I want to flush my clutch fluid. Is the fluid still good? I'm pretty sure it is but I just wanted to get some feedback for good measure.

Also, I have ~200mL left by the looks of it. Will that be enough for the clutch bleed? If not, I'll be mixing in a little cheapo Pennzoil to top it off. Any objections?

 

i usually flush the clutch with a pint of fluid. 3 weeks is fine.

 

As long as it's been capped it's fine.

I would not mix the two fluids.

I do find super blue stays cleaner a lot longer than standard brake fluid when used in the clutch.

 

Thanks for the info guys. Just a few more questions...

Does quality of fluid really matter in the clutch? I know Billman said ATE stays cleaner longer, but I want to do this today and I don't have enough ATE for the job. The manual recommends Honda DOT3 fluid. I guess any DOT3/DOT4 fluid should be fine, right?

Also, as far as the brakes, I believe the manual says to only use DOT4 as a temporary replacement for DOT3. Can anyone tell me why it's ok to violate this instruction in both the brakes and clutch?

Finally, why can't DOT3 and DOT4 be mixed in the S2000 clutch?

 

I said dont mix the blue and the reg stuff

If a system calls for dot 3, you can safely use 3 or 4.

If it calls for 4, you can ONLY use 4.

 

All DOT brake fluids are tested for compatibility with other brake fluids.
That is part of the DOT specification, in those exact words.
(Like with API motor oil spec)

It should do no harm.
You might end up with a mixture that is not as good as the seperate fluids but it will work.
Not recommended though.

I've used ATE SRBlue in my clutch system and I recently changed it with ATE SL.6.
That's a much thinner fluid and it made the pedal noticable easier to push.
Note: I have an "old style" ACT pressure plate.
It made the brakes a bit better too.

As far as I know, the main difference between DOT 3, 4 and 5.1 is the dry boiling point, "wet" boiling point and viscosity hot & cold.
The dry & wet boiling points go up with the DOT #, IOW: the higher the better.
The viscosity is lowest for 5.1, highest for 4 and 3 is in between.
They are all chemically compatible.

If a system calls for DOT 3 you can use 4 and 5.1
With DOT 4 the fluid may be a bit thicker (so ABS might work a little slower).
If a system calls for DOT 4 you can use 3 (in theory) and 5.1
With the DOT 3 fluid in a high performance car you might get some brake fade during a spirited drive as the boiling point is lower.
So its not recommended

IMO DOT 5.1 outperforms 3 and 4 in every way.
(except in price and maybe service life)

Most important: DO NOT USE DOT 5
DOT 5 is silicone based and NOT COMPATIBLE with 3, 4 and 5.1
Not even after a flush, the brake/clutch system itself is NOT COMPATIBLE.

 

Well it turns out I had more than enough ATE. I used the Pennzoil to flush the system and then filled with ATE. I was surprised at how little fluid it takes.

Thanks for your input Spitfire. Interesting that your clutch pedal felt different with the thinner fluid, mine feels about the same with Type 200.

And thanks too, Billman. Your wisdom has helped me more times than you know