Y61 ZD30 Sqeaking clutch

Just sharing some info. Had an annoying clutch sqeak that come and went. After using heaps of different sprays around top of clutch pedal that did not work, I had it inspected and some of the spring bushes were broken. At least I thought I found problem. Nissan does not sell the bushes anymore, you have to pay for $300 for a new pedal assembly .This was installed, but the irritating sqeak was still there! It was the booster . You can re kit these but not fix the noise. Nissan just quoted me a new one for $1200 , installation extra if needed. Could not find a second hand one, but sore a after market one on Ebay for under $200 (new). Got the brake and clutch experts in town to install it in case it needed ajustments.
Nearly a day waiting , and then to find out for some unknown reason it did not work. Pedal sticks to the floor, vacuum valve wont release. They said it must be a dud! So the old booster is back in and another $300 for that exercise. Possible that the TD boosters and ZD may be different, even though they look identical. So far a costly exercise and I am back to the square one with painful sqeak and squawk when driving. Someone said , "turn up the radio" , that is not an option :)
Ian Bundaberg