Cooling system pressure tester


In stock


Mazda Rotary engine cooling system pressure tester

Use this tool to pressure test the cooling system on a used or freshly built engine to ensure the water jacket seals are functioning correctly.


  1. Ensure all water lines on the engine are properly sealed, typically by installing an inlet manifold and plugging the heater line.
  2. Install valve and pressure gauge into tool
  3. Install the tool in place of the water pump, ensuring a good seal. We recommend vaseline to lubricate the o-ring.
  4. Pressurise engine cooling system to 20 PSI via the valve on the tool. Do not exceed 20PSI.
  5. Monitor pressure drop over 1-2 hours
  6. Small leaks may be identified more easily by using a spray bottle with soapy water on the outside of the engine.
  7. For a new engine that does not hold pressure, it may be required to add coolant to the engine and repeat the procedure to more easily identify the leak.

Fits all Mazda rotary engines except early twin distributor models.