Hi Charlie. I think you need to check if you have dot 5 or dot 5.1 dot 5 is silicon and you must not mix it with other types of brake fluid. dot 5 will not attract moisture and therefore you shouldn't need to change it. When it came out it was touted as being great for racing due to its higher boiling point. However it is somewhat more compressible than normal brake fluid which gives a longer or spongier feel to the brake pedal so it fell out of favour. when it is fresh it is often purple but with time it changes colour and eventually ens up yellow ish or clear. Hope this helps. John.