Why is my clutch sticking?

QMy motorhome recently developed a clutch problem, which is proving hard to diagnose. The symptoms are: after driving for about half an hour, the clutch becomes sticky on release to such an extent the clutch pedal remains depressed at traffic lights or is delayed to the out position on changing up or down gears. I have used my foot to release the pedal.

I searched the internet and, after discussion with my garage, we both agreed to have the slave cylinder renewed (£200).

A test drive after the repair led to the same problem occurring, albeit after a 45-minute drive. Both I and the garage are at a loss as to what to do next. Once the engine has cooled, the problem disappears. The next option is to replace the master cylinder (£200) and, if still not working, replace the clutch (£1,000). I would appreciate your thoughts on this issue.

Geoff Skerry

AA year or so ago I had a query from a reader with the same symptoms, but it was not until we got into a long conversation that I figured it out. His wife liked the heating directed to her feet in the winter, because she always had cold feet but he wasn’t concerned about that when he was driving.

The heater vent in the passenger footwell points directly at the clutch master cylinder. This gets much warmer than it is happy with and starts to deform. Only slightly – but enough to make it stick.

Initially, they tested my theory by requiring the wife to wear thicker socks and tuning the heat down a little. This worked well.

Later, I believe they asked their garage to fabricate some sort of heat shield to direct the heat away from the clutch pedal and/or insulate the master cylinder. Now, I understand that the wife can sit in open-toed shoes even in the depths of winter!

First I would reduce the amount of heat diverted into the footwell and, if the problem goes away completely when the warmer weather arrives, you have your answer.

Nick Fisher