Vibration

[Tanz]

For the last couple of months, I have had a loud vibration coming from somewhere in the car. This would happen completely at random. I would be on the motor way with no vibration then , for no reason, the vibration would start. This might last for 10 mins and then it would go again. This happened several times on the way to the 60th celebrations and was quite scary sounding like a wheel was about to fall off. On the way back from Hethel, while filling up with petrol, I noticed that the rear passenger side wheel was much warmer than the drivers side. Since then, the vibration has mysteriously stopped.
As the MOT is coming up I decided to do a few checks. The rear brake on the wheel that was getting hot has not got much brake pad left - the drivers side has got loads of friction material left. Seems that the vibration was caused by the caliper piston getting stuck and holding the pad too tightly on the disc. Took the caliper off and I can't push the piston back in so looks like I will be phoning Mike T in the morning for a new one. Actualy - when I was at the last 'a good night out' Mike did give a few causes for vibration and sticking caliper was one of them.
Notice the difference in pad thickness in the picture below