300 ml sounds plenty to me, especially if you syringed out the top bottle, the pipe run and what's left in the master cyl is very small
That's reassuring. Any idea of how much will be in the brake lines if I do the same, as they are next on the list?
For what it’s worth:
Typical brakeline is 3/16” external diameter, which is equivalent 4.76mm. Pipe wall thickness is 0.71mm. Doing the Maths, that equates to a volume of just 8.763 ml per metre run. So by measuring the overall length of your brake pipes, you can easily calculate the volume.
However, much of the overall volume will be in the reservoir and caliper/brake cylinders, the latter being much more difficult to measure. Colour is as good as anything to satisfy yourself that old fluid has been displaced. A litre bottle will be plenty to do the brakes and clutch with a bit left over. (Which should be disposed if as it is hygroscopic, so no good for future use)
