Got to replace all the oil in shimano brakes as its shot, loads of stuff on bleeding them but not a lot on replacing the oil.

Is it basically the same or do I drain the system totally then refil it – wary of doing the latter as don’t want to introduce air but the former may lead to contamination

HELP!

Just a normal bleed will do it. Plenty of guides around on how it’s done but Shimano are the easiest brakes to bleed.

How old are the brakes? If they haven’t been bled for a while then its worth doing a full purge and replace as its amazing how much crap gets in there. I found that when I bled my 2 year old Deores (new version) I needed much more than the 50ml (25ml each end) provided with the Epic bleed kit to do a full flush.

What I do with my XT is very full syringe at caliper, empty at lever. Push the fluid through until caliper syringe is empty, but there is fluid in the tube. Shut bleed valve and use caliper syringe/tube to suck out crappy oil from lever syringe. Get rid of this and repeat until fluid is clean coming out of caliper. Then bleed as per epic bleed advice.
I was also advised to use Citroen transmittion fluid (LM3 I think) as its mineral oil but a fraction of the price of shimano oil.

Cheers chaps, good advice and will give it a try

I had to swap my oil out on a Sunday afternoon so Halfords oil had to do as it was all I could get. It’s a different colour to Shimano so it was easy to see the old stuff come out. Nice and easy to do

Citroën LHM suspension fluid is the same stuff (Halfords)

shimano oil seems better, and thinner?

Draining the system is the worst thing you can do as it will fill the system with air, which you will need to remove later. It is far easier to use a little extra fluid than usual and simply push new fluid through from the calliper.

The reason our bleed kits come with 50ml of oil is because this is plenty for an everyday bleed – removing air. Replacing the fluid, or purging the system, with new takes additional fluid to be sure all of the old stuff is flushed out.

Thanks – so what volume are we looking at for a set of brakes (front and back)?

Cheers for all the advice – piece of cake when I got to doing it.