What causes a cylinder to leak?
What causes a cylinder to leak? If you fail to replace your brake fluid, the moisture content leads to internal rusting that will deteriorate the cylinder bore leaving holes. Worn piston seals made out of rubber will wear out and become brittle due to age. A cracked piston seal will allow fluid to leak past the pistons. What does cylinder leak-down mean? It's called a cylinder leak-down test. A leak-down test can tell you if the loss of compression is due to things like worn rings, burned or stuck open valves (intake or exhaust) or a leaking head gasket. You...