Timing belt replacement on a Citroën C4 My Citroën C4 HDI 110 diesel is eight years old, with 93,000 miles on the clock, but runs well due to regular servicing. Financial constraints mean I need to keep it for another four or five years and I have decided to have the timing belt changed (a little early), along with pulleys, water pump and so on. Is this wise and should I be considering any other replacements? Without doubt this is a smart move. And don't skimp by giving the job to someone cheap that is unfamiliar with this engine. If the brake fluid has not been changed for a few years, get that done as well.