To avoid expensive dealership's trying to trace a fault I decided to invest in a Foxwell NT510 BMW/Mini multi system scanner, and this confirmed that the brake vacuum sensor was showing a error code 4AFA, checking online it looks like part No.34336786746 is required looking at parts list this sensor was fitted on vehicles with stop start across both BMW and Mini with differing part numbers for different years, but they all look like they are fit to the vacuum reservoir the same.

Whilst this link is a Foreign site it shows the part and location.

http://mini.zaptrade.ru/part/catalog/VT/region/ECE/model/Cooper/engine/N16/serie/Cou/submdl/53627/proddate/20120400/len/L/getr/N/group/34/subgroup/34_1795/language/en/pid/1223

Does anyone know if its possible to fit without taking the vacuum reservoir off the car, looking pictures of the part its just looks like a serrated push fit connection into the vacuum tank, my guess is they don't pull out easy or push in that easy as space don't allow for large hands.

Information to those that have stop start when this sensor fails you just get a warning of stop/start failure on the dash when the vehicle would normally stop start everything else works normally apart from stop start feature, whilst you can survive without this feature its just annoying this warning message keeps occurring.

So if anyone knows a easy way of fitting a new brake vacuum sensor it would be appreciated.

Looking at the diagram Dave it is probably just a push fit and so should be capable of being eased out?

I would agree. It won't be easy access of course but it will be push fit or quarter turn. When you have the new sensor in hand the fitment will be more obvious hopefully?

Thank you both for your comments, Phil yes I agree it looks defiantly like a push fit but as Jason commented its likely not going to be easy job due to limited access.

I would imagine the bmw/mini dealerships may possibly remove the complete vacuum assembly unless they know of a easy method.

As this fault only effects the stop start I'll probably leave until warmer weather just in case I end up having to remove the complete vacuum assembly along re-bleeding the brakes, just a little bit too cold laying down on a concrete floor bleeding brakes, which I'm hoping to avoid as it was only a few months ago I completed the brake fluid change.

Dave, Just a thought.... perhaps give your nearest dealer a ring and ask for the price of both the sensor as a spare part and the cost of having it replaced by them..... the differential in cost will give you a very clear indicator of how complex the job is and you'll be able to tell if its a quick swap out or a disassemble job!

I just did this with the fitment of the LED DRL's.... The £300 fitting charge, gave me an idea of how labour intensive the job was and made me do it myself!

Thanks Jason that's a good idea I'll see what they say.

Looking on REALOEM site I see the part number I quoted has now changed it also shows what BMW and Minis are fitted with the same sensor.

http://www.realoem.com/bmw/enUS/part?id=SW32-EUR-04-2012-R56N-Mini-Cooper_D_16&mg=34&sg=27&diagId=34_1795&q=34336786746

Just got a price of the part only £133.48 from mini stealership still waiting for a price to supply & fit.

This is one very expensive sensor

Update

Really pleased I finally got it fixed today by Will at TWG Automotive for a reasonable price, Will obviously has a easy way to change this sensor.

Good news Dave