i have by mistake put brake fluid in the coolant?

The bike is fixable but it won't be cheap, you're probably looking at 2/3 hours labour plus parts. bike shops can charge around £50 per hour + vat. The cylinder head might need to be skimmed if it got damaged so that's an extra cost on what i've mentioned already. If you're going ahead with the job then ring around for the best price.

steo
June 2009