Question: how do i know if clutch fluid is bad?

[ptnov]

Hi,

I just noticed my brake fluid in the clutch master cylinder is alot browner than my brake side. I talked to a friend who's a mechanic and he said it clutch fluid isn't all that important and that it'll probably work without changing. He suggested that i wait to next time my brake fluid needs changing since it get alot hotter and it's much more important to keep that fresh.

So the question is how do i know if the clutch fluid will need replacing, and what are the dangers of keep driving with brown clutch fluid?

Thanks!

 

[maleko89]

If it's brown, it should be changed. I change it every other year.

 

[gamorg02]

my clutch fluid goes brown much quicker than the brake as well though. but yea every other year is what yamaha calls for too IIRC.

 

[maleko89]

my clutch fluid goes brown much quicker than the brake as well though. but yea every other year is what yamaha calls for too IIRC.

Garrett, mine does as well. Not sure why that is unless it's because of the slave cylinder allowing shit to get in.

 

[jfeagins]

IMO, clutch side turns browner faster because it is getting a whole lot more use! Think about it - a whole lot more use.

I change both clutch & brake fluid in all my bikes every year. Spring maintenance issue for me.

I try to keep fresh carb fluid in them at least once every 2 weeks, but will sometimes stretch that to nearly a month as sometimes I just don't get enough ride time available.

 

[MaxMidnight]

The only accurate way would be to measure the boiling point of the fluid.
Have a look here to see a bit more about brake fluid boiling point.
One other advantage of using Dot 5.1 that the author doesn't mention is that it doesn't attack paint - a considerable advantage for a messy sod like me!

Brake fluid is hydroscopic which means that is will readily absorb water. The higher the water content the lower the boiling point of the fluid.
In a braking system where high temperatures can be generated once the fluid boils you loose the brakes - not good!

Boiling is not likely to be an issue in a clutch system but the water content will be as it will encourage corrosion which will eventually damage the ferrous components.

To be certain that your fluid remains within spec. you should follow the manufacturers recommendation and change the fluid every two years.

 

[PATMAX]

Not to be rude but who cares? If there is any question it is so easy and cheap to change out and have peace of mind. Just saying.

 

[1st Shirt Maxer]

O.k. So I did a small experiment and was very surprised at the out come. Since brake fluid is hygroscopic (absorbs water) I decided to take a cup of fresh fluid and start adding water to it to see how much water it took to change color. I was able to have a 50/50 mix of brake fluid and water with very minimal color change. Sorry, I did not take any pics but the color of the brake fluid most resembled honey. Knowing that water will not only reduce the boiling point of the brake fluid, very important on the brake side to not boil your fluid, but water will also corrode the inner linings of your brake/clutch lines and components I feel that if your fluid is anything other than clear the you need to change it. I have seen fluid the color of coca cola coming out of people's master cylinders,which tells me that they do not get the proper servicing done in a timely manner. Just my 2 cents worth

 

[CaptainKyle]

not to be rude but who cares? If there is any question it is so easy and cheap to change out and have peace of mind. Just saying.

+ 1

 

[jfeagins]

I suspect brake fluid will change to a darker color for reasons other than water added. I'm guessing normal friction wear and pressure over time play a role in it's color change too. No way in Hades is there going to be that much water mixed in the stuff clear down by the wheel cylinders when time to change, but it still comes out darkened.

 

[[email protected]]

Not to be rude but who cares? If there is any question it is so easy and cheap to change out and have peace of mind. Just saying.

I suspect brake fluid will change to a darker color for reasons other than water added. I'm guessing normal friction wear and pressure over time play a role in it's color change too. No way in Hades is there going to be that much water mixed in the stuff clear down by the wheel cylinders when time to change, but it still comes out darkened.

+1 to both.