ddrag1

I have a 99 FRC with about 55k. Although I did not have a sticking pedal, I cleaned up the clutch fluid using the Ranger Method about 18 months ago. I used DOT 3 at the time and have continued to swap the fluid every couple of months with DOT 3. After the initial time, the fluid has remained mainly clear to amber (until today). About a month ago, I swapped it with DOT 4 and today I found my fluid to be black. I did another swap with DOT 4 today and after a short drive, it was black again. It seems unlikely to me, but could the switch from 3 to 4 have anything to do with the fluid being black? I'm guessing that the clutch components are just deteriorating more quickly and that it is just coincidental that it showed up when I switched from 3 to 4. Thanks in advance for any input.

deejbee

Mine was black as well and I put Dot 4 in it and it is clear now. Took about 5 times doing it for it to be clear.
I can't say for certain if changing from dot 3 - 4 would make it go black but I am a happy dot 4 camper now with zero issues. (1999 C5)

SVT_Z06

Yes. I experienced the same thing. I've used dot 3, and it stays clear. I swapped it out to dot 4 and two days later, it goes dark/black. Switch back to 3 and it stays clear. I have no clue what's happening. But I'm glad someone else has experienced the same thing. Maybe someone can tell us why....

v8srfun

I have no scientific proof of this but I am going to assume that dot 4 fluid Is lighter so when you switched it the other stuff in the system found its way its way up to the resivour faster than dot3

momo20

i hate to inform you but if your using the ranger method 5 times will not be enough to completely change out the fluid in your system...

v8srfun

I do not what the ranger method is (never looked it up) but every time I am under my hood I get out my fluid evaluator and drain the resivour and fill with fresh fluid. The car had 127k when I bought it and now has 131k the clutch pedal has slowly felt better after every fluid exchange

Pizzano

the main difference between DOT3/4 is DOT4 has a higher boiling temp, I would presume for tracking purposes or heavier braking conditions, as far as the fluid coming up black faster, maybe its cleaning out the system faster then DOT3, (dont know the exact chemical components between the two, but something is obviously happening)

deejbee

You are probably right.
I will do it 5 more times, then.
It takes all of 30 seconds to do, and I have lots of time.

deejbee

When we bought our car the clutch was so stiff I thought there was something wrong with it. Did the turkey baster thing and it feels perfect now. I was skeptical as to whether or not it would work but it definitely did in my case.