The OP wrote in his first post " The other day I stupidly put about 100ml of screenwash in the brakefluid reservoir " THEN " so booked it in for a brake fluid flush and replacement the next morning "

So when the fluid flush was done it would have distributed the screenwash throughout the braking system.

Water being heavier than brake fluid would fall to the bottom of any component ie slave cylinders & not exit via the bleed nipple.

I agree with full bleeding of the system after completely draining the master cylinder, that could be bled on its own by disconnecting the outflows so any screenwash in that master cyl doesn't end up in the calipers, and i would bleed the system again in a few weeks time, in case any screen wash has managed to avoid the previous flush through.

As Dieselnut says, it might not be that easy to get the stuff out the calipers if it gets there because the bleed nipples are at the top in order to assist expelling air, not fluid contiminated by something else, so extended pressure flushing would be my suggestion, i'd also be inclined to drain the brake pipes by disconnecting the lines at the last junction before each caliper, to less the chances of the stuff getting into them.

I would take action asap.

edit, if this happened on my own car i would retract and clamp each caliper piston down into its bore so the absloute minimum of space for brake fluid would be available in each caliper, that would make expulsion of the stuff more likely, its quite involved time wise but it's a relatively simple operation and only involves a G clamp or two.

Edited by gordonbennet on 22/03/2018 at 15:58