force tilt/trim

rice

Seaman Apprentice
Joined
May 25, 2008
Messages
48
hi everyone. just like to say thanks for all the info on here. i bought a 1989 blue fin 1700 with a 85 horse force. i completly redid the boat. i added a 39 inch live well, 2 bait wells, re did all of the wood, new controls, steering, stereo, carpet, seats, everything. the boat is like new. so now on to the motor. when i bought it it was running on 2 cylinders. i found a short in the wireing, taped it up, and now she purrs like a kitten. so the last thing on my list is the power tilt/trim. when i bought this package the motor was laying on its side and all of the "trim fluid" had leaked into the motor. i rebuilt the motor and it runs good now. i have removed the tilt/trim unit from the motor to try to troubleshoot and i am stuck. i am extremely mechanically inclined, i have repaired countless johnson/evenrudes in my life but this force trim system has me stumped. it dosent even move. the motor spins fine. it is coupled to the pump fine, but neither cylinder moves. i disconnected the line feeding the bottom of the trim cylinder and it pumps fluid through there but if i cover the hole there is not much pressure pushing on my finger. when i disconnect the trim cylinder return line no fluid comes out of the line, so i guess there is not enough pressure leaving the pump. i took apart the pump and it kind of looked like the pictures on this thread http://forums.iboats.com/showthread.php?t=209803
except mine has 4 1/4" hex bolts in a square pattern holding the pump together. i was not too sure what i was looking for in there but it looked spotless and it all went back together the way it came apart. i am using atf just because a industrial mechanic buddy of mine told me to, for all i know thats the problem right there. one more thing with the motor removed, and looking straight down at the top of the pump, there are 2 threaded chambers about 1 inch tall. only one of them has a allen head stud threaded about half way in and the other one has nothing threaded into the hole. if anyone has any ideas please help. thanks in advance
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
18,072
Re: force tilt/trim

If the motor turns and nothing happens then your hyd pump is bad.Jerry
 

rice

Seaman Apprentice
Joined
May 25, 2008
Messages
48
Re: force tilt/trim

thanks jerry. i am hoping to repair the pump. i am just not sure where to start. i am hoping that one of the experts can lead me in the right direction. i checked the check valves this morning and they look ok. im not sure how to take them apart. mine are the allen key type. thanks again
 

trophyforce

Cadet
Joined
Jun 16, 2008
Messages
10
Re: force tilt/trim

i have a 1994 90 force that had the same prob. i brought a rebuilt gear/pump from northern marine and when i installed it , it did the same thing. icalled northern marine back and they said keep the res. full of fluid and keepin going up and down with the switch until you get movement.giving the motor time to cool.wel after about an hour of this and one dead battery the motor tilted and i kept bleeding until all air was out and engine tilted up and down smoothly. even when i had the tilt motor and gear/pump in my hand and powered it up very little fluid drained out, northern said it will not because the pump needs pressure against it to work.hope this helps
 

rice

Seaman Apprentice
Joined
May 25, 2008
Messages
48
Re: force tilt/trim

thankyou soo much guys. i am at work tonight and tomorrow night but as soon as i get home i will try to get the pump up and down for a while to see if that works. i have ordered the parts to rebuild the check valves and i will replace them when they come in.

the guy i bought this thing off of swears up and down that it worked fine the last time he had it in the water, and then he had to do something stupid like leave the motor on its side in the grass for over a year and let all the fluid drain into the motor.

when you get air in the lines is it a common problem for the cylinders to not move at all? or should you still see some sort of movement. thanks again for all your help. you guys are great.
 

rice

Seaman Apprentice
Joined
May 25, 2008
Messages
48
Re: force tilt/trim

trophy force

when you say "i kept bleeding until all air was out and engine tilted up and down smoothly" did you have any fittings cracked or anything to get the air out, or did you just cycle up and down a bunch of times with everything together and tight? thanks again.
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
18,072
Re: force tilt/trim

Cycle,cycle,cycle. The unit should bleed the air itself.Jerry
 

rice

Seaman Apprentice
Joined
May 25, 2008
Messages
48
Re: force tilt/trim

thanks jerry. the cycle, cycle, cycle didnt do it so i decided to take everything apart. once i got to the tilt cylinder i found that the spring was popped out of its hole and broken. that was leaving a nice big passage way for the fluid to run free and do no work. it was the hole with the ball bearing on its side by itself. on the other side of the piston there are 2 balls. i decided to weld shut that hole. when i put it all together it came to life. now everything works flawlessly.
thanks to everyone who contributes to this forum. you people are keeping theese old motors around for generations. special thanks to clanton for all his knowledge on other threads.

now i still have one question. does anyone think that by welding this valve shut i have taken away the protection for when i hit a rock?. i figure that the way the fluid flows the other 2 valves on that piston are the ones that do that job. thanks again
 
Top