Recently I changed the rear brake cylinders. Both of them had one piston stuck due to rust. As the other piston worked (although with some friction) I did have rear brakes, but inadequate. My car went through the Norwegian equivalent of MOT autumn 2020, so either it was not detected by then or they have seized in the time after. Then I helped a friend of mine change his, all four pistons completely rusted and stuck. Also through MOT with no comments autumn 2020. Later I have talked to the local Morgan mechanic here in Bergen. He has had several Morgans in for service this spring and all of them - with no exeption - has had defective cylinders to some degree or other. You might not notice it as most of the braking comes from the front (my friend certainly did not in spite of having no working rear brakes at all), but this is obviously not what it should be like. So gentlemen, check your rear brakes. Take the drum off, lift the rubber dust cover over the pistons, check for rust, brake fluid leak and that the pistons move freely. If it is ok, apply silicone grease under the dust cover and put it back. If not, ......
The cylinders on my car has surely been in there since 2004, God knows when they started to seize. I changed to silicone brake fluid three or four years ago. I know it is disputed, but at least it is not hygroscopic. No issues so far, but it will be interesting to see if rust develops or not in the future. I will certainly check after each ended season, when the car goes into winter storage.
