Review on INNOVA 3619 Compression Tester Extension by Micah Manus

As mentioned before this distorts the compression reading as it doesn't have a valve at the end like a compression tester hose. Because of this, it effectively increases the volume of the cylinder, reducing compression pressure. That being said, I don't use it for compression testing, I use it for leaks. The absence of a pressure reducing valve does not affect the leakage results. My leak tester has a fairly thin hose, making it difficult to tighten the o-ring and get a good seal when testing engines with overhead valves. This extension allows me to have a good seal on the head and hose so I don't accidentally leak my o-rings into the tester. Combine this with Innova compression tester spark plug adapters and you can leak test just about anything you come across.