Brake cylinder

Need advice on Series 3 SWB 1983 brake cylinder. Pressed the brake when the drum was off and the cylinder popped out as attached photo. Is it repairable?

It may be as long as the seal is not damaged. If you carefully remove the cylinder, and fully inspect the seal. If it is still in good condition you may be able to carefully replace the piston without damaging the seal. Refit and test for leaks.

Take it out, clean it all carefully then refit it but as the seals are very cheap I would fit new seals. Lubricate with a little brake fluid when you assemble so the seal doesn't catch. You can hone the cylinders but they are not expensive and its hard to get them clean after honing without taking them off so once you do that you may as well fit new. Once brake fluid gets on the dust cover they can swell so you may have to get a seal kit as it comes with the dust covers.

Before playing with the seal, check the bleed nipple will move. If seized or if it snaps you will have wasted your time. If in a hurry refit seal if it is clean and undamaged otherwise fit a new cylinder. Wd40 on the pipe union and let it soak.

If you're stuck take the cylinder off, (if it will come off without damage and the bleed nipple will free off) clean thoroughly and refit the piston, using clean brake fluid as a lubricant. That piston looks rather scored and corroded so I'd replace the whole lot sooner rather than later.

Worth buying a little pot of red brake grease to lubricate seal and around inner of cylinder after refitting piston.
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