brake lines

[Jelco]

i am changing my lines. i have a bottle of golden spectrum dot4 that ive had since my last fluid change, about 12 months ago. is this bottle still good? i read/ heard that brake fluid can go bad. can anyone shed some light on this.

[mill916]

Since you're changing the lines anyways, it would be perfect to go up to a DOT 5.1.

[Jelco]

isnt that too strong? even though 85% of my riding is on the track, arent there any reservations for 5.1??

[CBR400RR]

Don't use brake fliud that has been opened for a while as it can draw mosture into the can.

[Bryant]

Ack.. 12 months? I would toss it and get a new bottle. Brake fluid is hydroscopic (it *absorbs* water). Old brake fluid that has been stored for that length of time is no good. Old brake fluid must be flushed out or water absorbed by the fluid eventually causes internal rust on the disk calipers and pistons, which can lead to all kinds of issues with your braking system.
Changing old brake fluid helps high temperature operation because fresh (dry) brake fluid has a higher boiling point than older (wet) brake fluid. If brake fluid boils, compressible gas bubbles form, resulting in a very spongy brake lever.

[Jelco]

thanks for the info- i got a new bottle.