bleeding my juicy 5s, front is fine, rear is full of cloudy/mucky fluid. What is the reason?

If i put new fluid in – how much will the system require? i have a third of a bottle of avid fluid but also a full bottle of dot 5. Is it worth replacing with dot 5?

Some dirt & crap always get past the piston/calipre seals, hense the murky fluid.

and so why regular bleeding (once a year) is recommended for the best brake performance.

Dot 5 is not compatible with normal dot5.1 – dunno what the avid oil is. A complete bleed thry takes a variable amount but 50 – 100 mls should do.

Your brake fluid looks like that ‘cos it is old – absorbs water etc

Don’t use 5 in avids. use 4 or 5.1

They don’t take a huge amount. I’d imagine the third bottle would do so long as it’s not been open too long. The murkyness of which you speak is a combination of water emulsifying in the fluid and dirt/swaft from the system when it was new. Brake fluid isn’t expensive. If it were me, I’d get a 250ml sealed pot from Halfords and flush both front and rear with it, really over do it and then not bother trying to store what’s left. having said that, at bleeding time, I have 3 bikes to do.

full fresh flush of dot 4 and bleed done 🙂