Springs lose pressure long before they look worn, and a set that has been on a hot engine for a season may not be doing what the box said. This is the affordable way to check them: a hydraulic gauge in a hex body that will sit in a bench vise or under an arbor press, so it works wherever you are.

Proform 66837 Analog Valve Spring Tester Features:

• Measures valve spring pressure with a hydraulic gauge.
• Hex-design body works in a bench vise or an arbor press.
• Portable enough to take to the track.
• Rubber gauge protector included.
• Sold individually.