1974 Johnson 135 HP Outboard Motors Service manual, Page 91Get this manual
GEARCASE PRESSURE TEST To test gearcase sealing, proceed as follows: 1Remove drain plug and screw in pressure test gaugeSee Figure 6-46Stevens Experimental pressure test gauge illustrated2Pump pressure up to 3- pounds Gearcase must hold 3- poundsIf pressure gauge indicates leakage, submerge gearcase in water to determine source of leakage as evidenced by bubblesIf gearcase pressure gauge does not indicate leakage, increase pressure to 16-18 poundsPressure should also hold at 16-18 poundsIf pressure does not hold, submer ge gear case in water and check Cor source of leakageMake necessary repairs and repeat testGearcase must hold within the range of 3-6 pounds and 16-18 pounds pressureFILLING GEARCASE 1Place gearcase in an upright position in suitable fixture2Remove oil level and oil drain and fill plugs3Fill gearcase with OMC Sea-Lube Gearcase Lube until lubr icant appears at 011 level holeSee Figure 6-47Insert and tighten oil level plug first Install oil drain and fill plug4Inspect gearcase oil level after motor test