A common problem with Mk I Renault 5s as they get older is leaking or siezed brake limiting valves. They are specific to the Renault 5 and limit the pressure being sent to the rear brakes. As more weight is in the rear of the car, the valve is automatically adjusted (by suspension deflection acting on a rod) to allow more braking force to the rear brakes.

The valve on my Gordini Turbo appears to be leaking, so I posted a topic to the forum explaining my plight.

After further investigation, it's very diffiuclt to tell if the valve is actually leaking. I got my wife to stamp on the brakes while I watched for fluid and I couldn't see any. No drips, nothing...

I got a siezed valve from a scrap car and have managed to free it off, but don't know if it works or whether it leaks. Changing the valve is a fiddly and time-consuming job, so I'm going to wait and see whether my original valve really does leak...

Note: it's my belief that the valve fitted to the Gordni Turbo is different from that fitted to other models.