Gearcase Pressure/Vacuum Tester

Product Overview

Stop water intrusion before it destroys your lower unit. This professional-grade combination tester allows you to pull and hold both vacuum and pressure with a single tool.

Engineering & Design

• 2-in-1 Design: Flip the valve to switch between pressure and vacuum testing.
• Universal Fit: Includes custom brass adapters for Yamaha, Suzuki, Tohatsu, Mercury, Johnson, Evinrude and Volvo Penta.
• Quick Disconnects: Brass swivel fittings make installation fast and prevent hose twisting.
• Superior to OEM and aftermarket: 90890-06756, CDI 551-34PV, S-34, V-34.
• The Inner Seal (Pressure Test): The lip faces inward. Its job is to keep the gear oil INSIDE the lower unit. You test this by pumping positive pressure into the gearcase and watching the gauge to see if it holds.
• The Outer Seal (Vacuum Test): The lip faces outward. Its job is to keep lake/ocean water OUTSIDE the lower unit. You test this by pulling a vacuum (negative pressure) and ensuring it holds.

Technical Specifications & Fitment

• Dual Function: Dual-Action (Flip switch for Pressure or Vacuum)
• PSI Gauge: High-visibility, highly accurate dial for slow leak detection
• Connection Type: Brass swivel quick-disconnect
• Universal Adapters: Mercury, Mariner, Johnson, Evinrude, Force, Volvo
• Comparable OEM and aftermarket part numbers: 90890-06756, CDI 551-34PV, S-34, V-34