brake fluid vs clutch fluid life expectancy

rob83ke70 · Post by **rob83ke70** » Sun Jan 18, 2009 4:48 pm

has anyone noticed that their clutch fluid absorbs moisture more quickly than their brake fluid? any speculation as to why this is so?

I'm thinking that due to the amount of fluid in the system being much less, the same amount of moisture is absorbed in both, but the percentage of moisture is greater in relation to the clutch fluid as the total fluid capacity is smaller.

any other ideas?

my boss thinks the electronic brake fluid tester isn't accurate. the clutch fluid was changed with a new hose fitted to a subaru forester, and about three weeks later i tested the fluid doing a service and it was 5% moisture on the electronic tester.

I'm not so sure that I doubt the meter though.

Robert.

TW83 · Post by **TW83** » Sun Jan 25, 2009 8:22 am

It may be to do with volume vs exposed surface area as you suggest. What about trying an experiment with 3 identical containers, 2 open topped with differing volumes of fluid and 1 sealed. Place them in the same loacation and test every couple of days. ???????

AlpineRaven · Post by **AlpineRaven** » Sun Jan 25, 2009 9:20 am

hmm... leads to bring a question.. how often you should replace it?? (Brake and Clutch fluids) Did mine about 2 yrs ago and have the feeling should do it asap!
Cheers
AP

Matatak · Post by **Matatak** » Sun Jan 25, 2009 11:18 am

Brake fuid generally is every 2yrs/40,000Kms to replace and flush it through.

3 weeks for the cluthc fluid Rob to get 5%!! moisture is definetely way to fast.

rob83ke70 · Post by **rob83ke70** » Sun Feb 01, 2009 12:58 pm

gotta be air getting in there somehow, via the seal at the cap i'd imagine...

gotta love it when the fluid goes black.... small particles of seals present in the fluid....

I was told by a fella at a brake and clutch specialist workshop that if brake fluid was changed when it needed to be in every vehicle, he'd be out of work....

Robert.