Thankyou Phil and Richard. The Servo has never been stripped ( by me anyway) but I did fit a non return valve in the hope that it would help. It did not. I have got the White plastic diagphragm as a spare and after doing the check suggested which, if it Fails, I canfit a new one.philthehill wrote: ↑Sat Aug 03, 2019 9:20 pm With a servo fitted you should be able to lock the wheels without difficulty.
Has the servo been stripped, examined and rebuilt. Is the servo diaphragm serviceable?
Will do this over the Weekend and Report back, if I may?