View Full Version : Shelf life of Motul 600 RBF

12-15-10, 01:28 PM
What's the concensus on keeping Motul 600 RBF around in the garage after you've opened the bottle? I picked up a small bottle to change out my fluid per the Ranger Protocol Clutch Care write up (below), and i've done it 3-4 times over the past few months as the fluid gets darker. How long can i continue to do this before the fluid goes 'bad' ? i've only poked a small hole in the aluminum seal to pour from and keep the cap on after use... thoughts?

12-15-10, 02:16 PM
Another aspect of risk is using brake/clutch fluid from a can that's been open for months or left with the cap off for an extended period. That's ill-advised. But I routinely keep a can going for 30-60 days by....
(1) cutting a slot in the membrane at the neck vice removing the entire seal
(2) replacing the cap when not pouring from it
(3) keeping the can in double layer of double-seal zip-lock bags between uses

Those steps minimize moisture infiltration to a can that's been opened.

I was reading the Ranger Protocol that you linked to and he answers your exact question.

12-15-10, 02:34 PM
Whaddya know.... must've skipped over that part. Thanks!

12-15-10, 07:11 PM
Isn't the problem that it absorbs moisture from the air? Once you open it, air with humidity will get into the can. How much moisture does it take to go "bad", and how can you measure the moisture content of the fluid to know if it's still "good"? I suspect it's difficult to tell, hence the advice to use a can up once you open it.

I want to say the wet boiling point of brake fluid is with like 2% water absorption, it's not tons of water.