Why does your Porsche’s brake fluid need changing regularly?


Some Porsche owners we meet are reluctant to have the brake fluid changed in their cars at regular intervals - until we’ve explained exactly why it is an important part of a good maintenance regime.

There is a belief among some motorists that brake fluid has the same lifespan as cars and that the recommendation that it is changed every two years is just a money-making ploy by dealers and independent garages.

Both parts of that assumption are incorrect, as not only does brake fluid have a limited lifespan, changing it regularly can help to keep down your long-term maintenance bills.

The brake system in a Porsche is not 100% sealed, so moisture gets in and is absorbed by the fluid. Over time, this eventually leads to a spongy feeling brake pedal and impaired braking performance.

The science behind this is simple. Pure brake fluid has a very high boiling point to enable it to cope with the temperature generated by the friction involved in sharp braking or controlling speed on a steep hill. Its boiling point falls once it has been diluted by the moisture it absorbs, which means you have to apply greater pressure than should be required on the pedal to slow the car when travelling downhill or trying to stop quickly from high speed – an obvious safety issue.

Brake fluid that has been contaminated by moisture can also cause corrosion and pitting of metal components in the brake system. Compare the cost of replacing, for example, an ABS pump or a caliper with the price of adding a brake fluid change to your service, and it is clear which is the more affordable option.

It is also important to remember that a lack of maintenance/brake fluid change will also mean the high risk of the bleeder valves being seized into the caliper, meaning either additional costs in engineering work OR the very expensive cost of replacing one or more caliper

Your owner’s manual will indicate how often the brake fluid should be changed in your Porsche (usually every two years) and which fluid should be used. Low mileage makes no difference to the rate of moisture absorption, so the recommended time-based schedule should be followed.

At Revolution Porsche, you can add a brake fluid change (using the recommended fluid) to a major or minor service for £65+VAT. Contact us for details or to book your Porsche in.