I remember reading somewhere about how mineral oil loses performance over time (takes in moisture I think ?). Does this mean that brakes should be routinely bled every, say year, to maintain tiptop performance ? I don't think I have touched one of mine for best part of 2 years and I can't say i notice any problems with it. Or is it a case of 'if it ain't broke….

thoughts ?

6 years on my 525s without looking at them, fine in the Alps last year…

When they get spongy

Mineral oil, iirc, is far less susceptible to degradation in performance than DOT fluid is.

dot sucks in moisture – mineral should be ok

aha….., so same question then for my Hope's – don't think I have ever bled the front one and it's about 18 months old…..

Any ideas on how to minimise lever movement before the bite point on the new M810 saints? The little srew adjust doesnt seem to do much.

As others have said mineral oil is far less susceptible to degradation than dot fluid. with dot fluid you should do an annual bleed thru as the water absorption reduces the boil point.

Both types of brakes the fluid will slowly contaminate. microscopic wear particles, tiny bits of seal even dust drawn past the seals and mineral oil will degrade eventually.

Its preventative maintenance. I do my hopes at least every year. It takes 5 mins and costs pennies in fluid.

If I had shimanos I'd do them every couple of years or so

thanks all. Might bleed the front Hope this weekend then….. -)

Shimanos? Bleed them when(if) it feels necessary. I have a set of 5-year old Deores which have never been bled.

druidh – bet the fluid is contaminated by now 🙂 It is certainly far less important with mineral oil brakes. Depends on usage rather than time I guess with mineral oil rather than time which is more critical with dot fluid.

TJ – WGAS as long as they're still working?

last time I bled my Shimano deores was when I put them together 3/4 years ago. I keep thinking about doing it, but I'm too busy riding…May do it this spring, everything's due an overhaul then anyway.

druidh – you might increase their life? Its a fairly marginal thing and I do admit to a touch of OCD on mainenance

i have a set of 525's on the s/speed that are as good as the day i got them, and some xt 775's on the other bike which have to be honest been sh*te, the back constantly needs bleeding just cant seem to get on top of it, have done it with a syringe at the caliper and the bag method

I do admit to a touch of OCD on mainenance (sic)

Nowt wrong with that, I get really really pee'd off if they're not running "just so". Plus I reckon long term it probably saves money on replacement parts if you look after what's there already.

525's are the King of brakes, aren't they?

OK they're effing ugly and a bit portly, but pads are cheap, they work consistently well, easy to bleed (not that I do, or they need them) and with a decent rotor can give pretty good performance. Keep looking at more flash brakes but I honestly can't justify ditching the Deores…