For: 1991 OMC Evinrude 40HP, model E40TLESRThe seals at top of the trim/tilt cylinder are leaking. In my first attempt to replace the top seals and also the internal seals within the power trim/tilt cylinder, are there any cautions or tips that I need to be aware of to successfully replace all the seals? I'm also concerned about any problems regarding air space within the cylinder after re-inserting the piston and closing the cap? Should I fill in as much fluid at top of cylinder above the piston before closing the cap?