Clio Brake Problem

[piston_*_broke]

New Clio 1.5 CDI

About once every 2 days, the brake pedal goes stiff, and more force is needed to brake, which of course causes "vigorous" braking.

Renault dealer had car for 4 days, on numerous test drives it did not happen, so they are "unable to do anything until we can replicate the Fault".

Has anyone any suggestions, or knowledge of this as a fault. by the way, the service managers car has the same fault....

happy motoring, all.

Of course logic might state that you may just have a pedal that's done up too tight somewhere, but I'm sure you've checked that.

My old Clio had the complete opposite problem - pedal went pretty floppy and not much braking happened at all. This was caused by the master brake cylinder losing pressure every so often and consequently the brakes not being applied hard enough by the car. The reason I say this is because perhaps the opposite is happening here....too much pressure? I don't know if that's technically possible or whatever but maybe worth asking about?