JAD said:
Update to this and to answer a few points raised by Tom etc.
I've told BMW I'm not happy for a few reasons - they told me it was over tightened, it's only been to BMW in its life. They then went down the corrosion route which I questioned why a loosening agent wasn't used first and why, if this was so common, the service person did not check all nipples before pumping new fluid into 3/4, they haven't really come back with an answer. I mentioned I live in London and this was a Cheshire based dealership so have told them I will not be back up until at least December to redo the fluid change and there was no quibbling over payment.
I'll be writing off to BMW to try my luck with an argument of poor service standards (should be told of the risks, should be checking all four loosen before changing fluid in three out of four, should not be telling customers they've done the job when that's impossible/not true). I'll see where this gets me. If it is a regular occurrence, due to corrosion, I accept that. I can afford the bill, but I'm not a moron, blindly accepting a £1k bill...!!
- car is fine to drive - no spongey brakes.
- I've been in touch with a few garages; some quoting £100 for it to be drilled out or £250-400 for new caliper fitted and full bfc service, so will be going down that route.
I think you're quite right to write to them, I agree with where you're coming from though I don't hold out a lot of hope that it will achieve much. Poor service standard is one of their fortes. As teamemmenracing pointed out, they should have inspected and warned you, on the other hand though there is always some kind of risk working on old parts, that's why the guarantees don't go on that long.
I'd love to see how they arrived at a £1000 bill though, even for BMW that's pretty insane!
Personally I'd be looking at a decent 2nd hand caliper like one I linked earlier and fitting that.
It just goes to show really imo that any work that doesn't need to be done by bmw (i.e. other than oil & inspection services assuming you want to keep FBMWSH) is far better done at your specialist of choice.