Diesel Compression Tester Replacement Sealing Washers

When doing a compression test you must properly seal the inner surface of the pre-chamber with the fuel injector hole adapter. Copper washers work the best for this to ensure a 100 percent seal. Do not use the engine's heat shield washers. After a few uses, these will flatten out and must be discarded. As of February 2021, we are shipping our compression testers with four of these sealing rings.  It is good to have extras if you plan to do multiple compression tests.