Mercury 40 Service Manual page 501

NON-BIGFOOT GEAR HOUSING
Gear Housing Pressure Test
1. Remove vent plug and install pressure test gauge. Tighten securely.
2. Pressurize housing to 10-12 psi (69-83 kPa) and observe gauge for 5 minutes.
3. Rotate drive shaft, prop shaft and move shift rod while housing is pressurized to check
for leaks.
4. If pressure drop is noted immerse housing in water.
5. Re-pressurize to 10-12 psi (69-83 kPa) and check for air bubbles.
6. Repair leak as necessary. Retest housing.
NOTE: It should hold 10-12 psi (69-83 kPa) for 5 minutes.
7. Remove tester from housing and install vent plug.
Page 6A-46 90-828631R3 MARCH 1999