"Ceck your service manual" is not a generic answer to post to peoples questions on this sight. There are A LOT of people with A LOT of experience on this forum that can really help people. People with problems on this sight need to be specific but people with experience need to also ask the right questions before giving a diagnosis. I am an M1A1 tank mechanic, which believe me, is a complicated beast and one of the first things we are taught is ask a lot of questions about exactly what the crewman were doing before their cr*p broke. You can figure a lot of stuff out by taking the time to dig into these details before even breaking out the first tool.