PROFORM 67400 Spark Plug Air Hold Adapter Kit, 14 mm and 18 mm Threads

The PROFORM 67400 Spark Plug Air Hold Adapter Kit provides a reliable connection between an air supply and a gasoline engine’s spark plug opening during valve train and cylinder head service. Designed for use with compressed air, this adapter helps maintain cylinder pressure so valves can remain supported while springs, retainers, seals, or related components are serviced. It is a practical tool for professional technicians, engine builders, and experienced automotive DIY users.
The kit includes adapters for common 14 mm and 18 mm spark plug thread sizes, helping accommodate a broad range of applications without requiring multiple separate tools. The air fitting design allows connection to a shop air source, while the spark plug-style threaded ends provide a secure interface with the cylinder head. Always verify the correct thread size and use appropriate air pressure for the engine and service procedure.
PROFORM part number 67400 is intended for controlled shop and garage use where dependable cylinder support is needed during engine maintenance. Its compact format makes it easy to store in a toolbox or engine service kit, and the straightforward design supports efficient installation and removal. Use the adapter with clean, regulated compressed air and follow the vehicle manufacturer’s recommended service practices for safe, accurate results.

Features:

• Spark plug air hold adapter kit for engine valve and cylinder head service

• Includes 14 mm and 18 mm threaded adapters

• Connects a shop air supply to the spark plug opening

• Helps maintain cylinder pressure during valve spring and seal replacement

• Compatible with many gasoline engine applications

• Compact design for convenient toolbox storage

• Brand: PROFORM

• Part Number: 67400