What brake fluid should I be using with a sierra master cylinder, sierra rear calipers and wilwood front calipers?

How much fluid am I likely to need?

I have 2 litres of Motul 5.1 synthetic fluid that has been sitting on a shelf for 2 years. The bottles are plastic and are unopened. Would these be safe to use still (if 5.1 is ok)?

Cheers

It will be fine, Dot 5.1 although fully synthetic is mixable with Dot 3 and Dot 4 fluids although you have enough for a full system so you would be using fresh fluid throughout. It's the Dot 5 silicone fluid that does not mix and gives you the spongy pedal.
Since you have it you might as well use it.

You won't use the half of it anyway, depending on what method you use to bleed it through.

[Edited on 27/5/13 by Scuzzle]