[Mike Pearson]

A leak down checker is just a tool. It is mostly used to diagnose an issue in the cylinders of the engine. its a comparison tool. If you have a baseline for the engine when it is performing properly then you have something to compare it to down the road if you are having issues with performance. Typically anything better than 10 percent is considered good. Leakage by the intake valve is the worst and even a small leakage past the intake valve will effect the performance of the engine. The exhaust is typically not as sensitive.