Is the brake fluid replacement part of the 3rd year service, or an extra thing to ask for?

It's definitely required at three years (regardless ofmileage) according to the service book. I wouldn't be surprised if you have to ask for it in addition to the service though and no doubt the stealer will want to charge extra for this!

I seem to recall on a previous VW being asked whether I wanted the brake fluid changing (two year change interval for that car), but they charged something like £40 in addition for the privilege.

At least the coolant doesn't need changing for 10 years!!

I flushed mine this weekend. It took longer to jack up the car & remove the wheels than it did to flush the system. I used 1.5 liters of Castrol LMA brake fluid & used this to flush the system:Black Label European Bleeder 0109 [url] http://store.motiveproducts.com/shared/Sto...=222434639





























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I would not bother to change the fluid untill the car is at least 5yr old

Brake fluid is hygroscopic (absorbs moisture from atmosphere) and therefore can have a water content after 2-3 years. This reduces the boiling point of the fluid, it also means you have some form of rust inducing content in fluid passing through all the expensive brake components.
An ABS/TCS hydraulic unit is about £900. All FL2's (3) Gone
2011 Mercedes C180 CGI Gone
FL2 GS Auto SD with heated leather, factory tints, alloy spare and a few other bits.

tonka, I change the brake fluid in all my cars every 18-24 months. You can see & feel the difference. When the old fluid is pushed out you can see how cloudy & dirty it is. The main reason for flushing is to keep the moisture out of fluid. As druand noted brake fluid is hygroscopic & our systems are not 100% sealed from the atmosphere. Here in warm & humid Florida our relative humidity averages ~ 90%. Land Rover service requires a brake flush every 3 years. Most others require a fluid flush every 24 months. I've been using Castrol brake fluid since 1973 and have had great luck with it. I learned the hard way when I used some other brand in my 1973 MG B and it turned all the rubber parts in the brake & clutch system into mushy peas. That was not a good feeling to my heart, wallet & knuckles. The Castrol GT LMA provides:

Unique Low Moisture Activity (LMA) formulation provides maximum protection against vapor lock brake failure.

Exceeds DOT 3 and DOT 4 requirements.

Maintains a higher boiling point than conventional brake fluids.

Superior protection against chloride and zinc corrosion of braking system parts.

Suited for Audi, BMW, Jaguar, Land Rover, Mercedes-Benz, Porsche, Saab, Volkswagen, Volvo, Honda, Acura, and many other brake systems.

Exceeds specifications SAE 1703, SAE 1704, ISO 4925, JIS K2233 and FMVSS No. 116 DOT 3 and DOT 4.