Only when the tip fits nicely with no endplay is the tappet properly adjusted, if the tip doesnt fit, OR if there is up and down endplay, the tappet is out of adjustment After adjusting the tappet, simply insert the tip of this tool under the hydraulic unit retaining clip, above the pushrod seat Will not work on Solids, JIMS Hydrosolids or other limited travel tappets Hand tool simplifies the way to verify proper tappet adjustment Made in the U.S.A.. TOOL HYD TAPPET GO-NO-GO