Speaking to our local Brake Mechanic Darall Richards, he passed on some advice about brake fluid. Here in New Zealand silicon brake fluid is about five times more expensive than the conventional type. It does not absorb water or corrode paintwork and has a long service life. The Brake Mechanic said that he had a car in storage for 11 years, with silicon brake fluid in the brake system, and after that time the brake system still functioned, how well he did not say. He recommended that if you wanted to use silicon brake fluid, every one or two years, pump the fluid through a fuel filter to remove any contaminants and to decant off any water in the system. The reason for this is that if water gets into the system it will sit in a lump and corrode the system at that point. If you are changing from conventional fluid to silicon, flush out the old fluid with the silicon fluid do not use anything else and vice versa, an expensive procedure. I have been warned by another Brake Repairer (Just Brakes) that flushing with methylated sprits is not on. Also replace all seals unless near new, the reason for this that the two fluids are incompatible and the old seals must absorb some of the fluid. The old fluid must be removed from the system and compressed air would help this process.

To sum up, Silicon is great for cars that are not used regularly, providing you can stand the cost and observe the installation procedures, on the other hand conventional fluid has to be replaced every 18 months (Darall says 12 months) which is a cost to the environment and is much cheaper. Another advantage of the conventional fluid is that it absorbs water, which is dispersed in the fluid and does not gather in a lump and provided the fluid is regularly replaced, the water is removed from the system