GearWrench Air Hold Fitting 2 Piece Set The GearWrench Air Hold Fitting 2 Piece Set Features:

Use to Apply Air Pressure to keep Valve Closed while replacing Valve Spring

Set Includes 14 and 18mm Adapters Threaded for 1/4” NPT

To use, Remove Spark Plug and Screw Air Hold into Port

Fasten Air Hose to Fitting and Apply Pressure

Use with 912DD, 2078D or 3271DD Valve Spring Compressors

Caution: Vehicle must be Placed in Park/Neutral before Applying Air Pressure, otherwise Vehicle may move

Keep Hands Clear of Fan, Belts and Pulleys since Slight Crankshaft Rotation will Occur</li.