Brake Fluid

Yep, its hygroscopic which means it absorbs water. Chuck it in the bin and buy a fresh bottle. Even if it's sealed, it's cheap enough.

 

If it's a sealed bottle (not just one which has its cap screwed on after previous use), then I don't think it will have absorbed water (plastic bottles are pretty impermeable). Personally, I would use it without worrying. If you are really that worried, save it for rear brake and clutch use?

 

Don't be tight and throw it. Brakes are the most important bit on a bike and for the sake of a fiver it isn't worth the risk.

 

Does it have a use by date on the cap??

 

This has been puzzling me. I have now checked several manufacturers' websites (Brembo, Putoline,Castrol, etc) and I can find nothing, including looking atheir techincal spec sheets, to suggest that there is a limited shelf life. I have also looked at containers I have on my shelf - Brembo and Shell - and I can find no dates or warnings about this. All of the information I see is consistent - do not reuse, always keep in original sealed container, always replace after a couple of years once installed in the braking system. So personally I would not throw away a sealed plastic container even if 5 years old or more. A 20 year old rusty metal container... that would be different!

 

If it's sealed, no water can get in there to contaminate it.
All the warnings are about opened containers.

 

People seem to get very precious, not to say obsessive, about brake fluid. Chill.

 

Check manufacturers technical depth. quick phone call in morning should soon get an informed answer as to what is safe.

 

You can tell just by looking if the fluids gone off, goes from translucent to dark gold and eventually black!.

If the foil seal is still intact it is more than likely ok to use.

 

The only comment I would add to what has already been said is that like technology, 5 years is a long time and things move on. If you are going to expect a lot of your braking, perhaps a check to see if your fluid matches the latest spec is a good idea. From personal experience, I have found that although more expensive, a race spec fluid that is designed to operate at much higher temperatures, provides more consistent performance where the reservoir is next to the exhaust. Andy

 

Put it in the microwave, it will drive out any water or dissolved gasses, then it'll be fine

 

:Wideyed:

 

dot4 fluid is dot4 fluid.

if its sealed its fine
.(you think brake fluid doesn't get stored for years by the manufacturers?)

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