Tilt/trim unit leaks down

Force 1988 85Hp 856X8A. <br />The engine leaked down and draged about 6 iches on the driveway I also backed up going nowhere fast! Thats how I found the engine had leaked down again. No the motor will not go up at all!<br />The tilt motor tries real hard but the engine does not move it seems the down works.<br /><br />Where do I get this spanner to take off the top of the tilt cylinder? <br /><br />Shuold I also replace all O rings and seals?<br />Can I get everything needed? I know O-rings are universal just get the correct diameter but what about the stuff in the pump?

Re: Tilt/trim unit leaks down

The pump has a couple of small o-rings in the check valves that can be removed from the side with an allen wrench. Internally there are no o-rings. I disassemble my pump a couple of weeks ago. There were only springs and ss balls internal. No need to disassemble it. I did find crud in one of the check valves.

Re: Tilt/trim unit leaks down

I was looking real close at the tilt/trim unit as a whole and notice there are 5 bolts holding the cap on the trim. I also noticed that 2 of the heads on the bottom are missing and the cover is slightly cocked on the cylinder. I think this is my problem.<br /><br />I will report back and post a step by step on the shareaprojects site later.

Re: Tilt/trim unit leaks down

The step by step was too hard. I worked all day to remove and fix the trim cylinder. This has fixed the issue for now.<br />Tilt/Trim pics<br /><br />Basically I was inspecting the trim cylinder and notice the top was a little crooked. I then looked closer and two bolts were missing to boot.<br />Internally the trim looked good but the o-ring was in two pieces.<br />I replaced all O rings in trim cylinder and the 4 bolts as I could not get 1 of the studs that was the remaineder of the bolt out. I will rebore this later and install a bolt. I had to get a different bolt than what was in the unit originaly as Merc does not have them anymore. I did find SS 1/4-20x1 3/4" With a hex head instead of the twelve point head. They look good and should be fine. <br /><br />Also the guys at a local hydrolic place found all but 1 ring for the trim unit. Oh and they gave them to me for free!! Luckily the local marine guys had that o-ring and thats it.<br /><br />In testing it all worked except the small leak that was a result of not tightening the line up DOH! <br /><br />Will test tomorrow I hope! If not then Tuesday.<br /><br />I was lucky there was not scoring or problems with the rest of the unit.

Re: Tilt/trim unit leaks down

Nice job -- Don't you love it when you don't have to replace anything major!

Re: Tilt/trim unit leaks down

Yes, but it was a P.I.A. job to do. I already did the hard stuff like the floor, controls wiring etc...

Re: Tilt/trim unit leaks down

hey guys im new, names mike... i have an 88 bayliner/trophy i just recent picked this boat up and the fitting on the trim pump was broken off i ordered the new bend strap and awaiting arrival... can you guys tell me how to fill and bleed the trim setup...


thanks any advice would be greatly appreciated


thanks mike

Re: Tilt/trim unit leaks down

There is a fill screw on the side of the resevoir where you fill the system. You bleed it y running it up and down a few times. Check the opil level and refill if necessary.

Re: Tilt/trim unit leaks down

chuckz said:

There is a fill screw on the side of the resevoir where you fill the system. You bleed it y running it up and down a few times. Check the opil level and refill if necessary.

Click to expand...

yup. zactly. use a old school diner style katsup bottle to squirt 30w NON-DETERGENT motor oil into the hole. As you go up and down the bubbles pass through the reservoir and float to the top.