Servicing an Evinrude power tilt, making sure the hydraulic fluid levels are where they should be, involves more than just looking at the fluid level and adding fluid if needed. It also means operating the system throughout its full range of motion to ensure that any air trapped in the fluid is moved to the hydraulic reservoir. Once at the open hydraulic reservoir, the air -- in the form of bubbles -- is released to the atmosphere. When the system is burped and the reservoir filled with fluid, the system is in good working order.
Items you will need
Hydraulic oil
Locate the hydraulic reservoir for the power tilt system. Remove the cap from the reservoir -- the fluid in the reservoir should come all the way to the bottom of the filler neck. Leave the cap off the reservoir until the service process is complete.
Raise the motor, using the power trim switch located on or adjacent to the throttle handle, to its highest position. Add fluid to the hydraulic reservoir if necessary.
Lower the motor to its lowest extent and check the level of the fluid in the reservoir. If the fluid is not even with the bottom of the reservoir's filler neck, add fluid until it is. Raise the motor to its full height once more, using the power trim switch.
Check the fluid level in the hydraulic reservoir, adding fluid if necessary. Repeat the process five or more times. If, after multiple repetitions, the fluid level does not remain even with the bottom of the reservoir's filler neck, inspect the area around the reservoir for evidence of leakage, including puddles of hydraulic oil. Pay close attention to the points where hydraulic lines connect to the reservoir.
Follow the hydraulic lines, inspecting them for leakage, to the hydraulic pistons (also called rams) that move the motor. Look for hydraulic oil on each end of the ram and around the point where the rod slides into the barrel of the ram, on the deck and on neighboring equipment. Replace hydraulic lines as necessary; rams and reservoirs require professional service.