Hydraulic leak

My 2009 Nissan Terrano II TDI is losing fluid from the clutch master cylinder. I have found a 5/16 in pipe feeding a bank of pipes running along the offside chassis, but I have no flaring tool for this size of pipe.

I have got the clutch working by removing the pipe and plugging the hole with the correct bolt and copper washer. Will this be of any detriment to the vehicle? I have tried to find out why this pipe is fitted as it runs from the block to the rear axle, where it appears to be blanked off. Would you replace this pipe or leave it as it is not leaking?

I am about to change the gearbox and rear axle oil – will SX 75W90 be suitable? Roger Booth The pipe that you are referring to was placed in the system as a damper and was intended to soften the feel to the clutch pedal. According to my sources, it is a common occurrence for this extension pipe to corrode and leak, and most owners do as you have done and simply blank off the outlet. Provided you are happy with the feel of the clutch, and that the blanking plug is firmly fitted and there are no leaks of fluid, which would also suggest the possibility of air getting into the system, I would be happy to leave this outlet plugged off.

The recommended transmission and differential oil for your vehicle is EP 80w90, which is a mineral oil. The SX75W90 is semi-synthetic multigrade oil, which is a perfectly suitable replacement for the gearbox and differential oil in your Nissan.