90 Bayliner 85 force trim problem

lotusing

Seaman
Joined
Jul 9, 2006
Messages
56
Well, problem #2.I wanted to service the trim and check the oil level and a local Marine shop said that AFT was ok to use in the trim.Well I added some and now the trim creeps down very slowly.I then called force manufacture(now Mercury) and they said to use 20 non-detergent oil.I flushed the fluid out and changed it but still creeps down.What is going on and is there a different oil to use?
 

lotusing

Seaman
Joined
Jul 9, 2006
Messages
56
Re: 90 Bayliner 85 force trim problem

Is that in the manual and is it easy to replace?
 

JUSTINTIME

Captain
Joined
Sep 2, 2006
Messages
3,284
Re: 90 Bayliner 85 force trim problem

very tough job
u need to lift the motor up
 

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Re: 90 Bayliner 85 force trim problem

Take off the pump body. That is the thing with the 4 hyd lines coming out of it. Disconnect the 4 lines and unscrew the 4 screws holding the body to the reservoir.
Now, if your pump has the screw in check valves, your job is easy. Using an Allen wrench, unscrew the check valves on the outside of the pump--one on each side of the pump. The quick and dirty fix is to replace them in reverse order since the up check valve seems to fail first, and you really don't need the down check valve. The proper fix is to remove the pressed on valve cap (part just above the O ring) I grab it with a cushioned pliers and twist and pull. Be careful! Don't **** it up! you need it again. under the cap you will see the check valve and the remains of the small O ring. Go buy one of these O rings in Viton and replace it. Carefully press on the cap and replace the valve assembly in the pump. If you have the pump with valves held in by circlips, these valves are not serviceable. To the best of my knowledge, no one sells replacement valves. Contact RRitt here and see if you can buy a pump from him. He will probably be jumping in here soon anyway. Pumps are his specialty.
 

RRitt

Captain
Joined
Mar 30, 2006
Messages
3,319
Re: 90 Bayliner 85 force trim problem

whoa ...

just leave everything on boat. don't take anything apart. don't undo any screws or oil lines. 1990 should have a round plug on bottom that unscrews with a hex key. There should be one facing directly forward and one facing directly back. Unscrew the front one and swap it with the back one. If that fixes it then you're good for a while. a day? a week? a month? a year? who knows. but it's free and easy.

if that doesn't fix it, then there are no easy fixes. Most of the parts you'll need are not available to the average mechanic or marina.
 

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Re: 90 Bayliner 85 force trim problem

Did you forget how close the back one is to the transom? To get it out, you need to either remove the pump body, or the whole motor/pump assembly from the clamp then bend the hydraulic lines, or remove the whole engine from the transom.
 

RRitt

Captain
Joined
Mar 30, 2006
Messages
3,319
Re: 90 Bayliner 85 force trim problem

yup. did forget. good thing you mention this ... I should try to figure out a way to get back valve out without having to take the pump off. It doesn't even make sense to try the cheap and dirty fix if it requires that much effort. By the time you go that far then you may as well just fix it right.

I think I'll muck around with this tomm. during lunch and see if there's a way to cheat.
 

lotusing

Seaman
Joined
Jul 9, 2006
Messages
56
Re: 90 Bayliner 85 force trim problem

Someone said that they had the same problem, took the old fluid out and put 30sae non detergent in and fixed the problem.What is the exact procedure in replacing old fluid with new.I understand that you have to fill it while engine is up then lower and raise motor while the fill cap is out.Does it not come all out.I have the engine down and took the fill screw out and fluid was coming out.Does this mean that it is over filled?
 

RRitt

Captain
Joined
Mar 30, 2006
Messages
3,319
Re: 90 Bayliner 85 force trim problem

run engine all the way up and block into place. take loose front bottom oil line and put bucket under pump. run pump up until resevoir is dry. take loose bottom tilt line. lower engine and old oil will be forced out of open tubes.

reconnect everything and refill. cycle once - it will probably stop lifting halfway up becuase no fluid left in resevoir. refill and finish going up. fully lower, top off resevoir, and put filler plug back but don't tighten. cycle 2-3 times up & down to flush out air. run all the way up and tighten filler plug just enough to seat o-ring around threads. you're done.

running thicker oil won't fix problem it will only slow the bleeding.
 

lotusing

Seaman
Joined
Jul 9, 2006
Messages
56
Re: 90 Bayliner 85 force trim problem

Well I check the fluid with the trim fully down and oil came out so I left the filler cap off and cycled up and down 3 times and it is better.It does go down only at the top then stops less than half way.Should I still flush the system or just keep cycling?
 

lotusing

Seaman
Joined
Jul 9, 2006
Messages
56
Re: 90 Bayliner 85 force trim problem

I just checked and it still went all the way down just took longer.
 

klmarton

Recruit
Joined
May 23, 2007
Messages
2
Re: 90 Bayliner 85 force trim problem

I have an 89' bayliner capri w/2.3L. Would my tilt have external check valves as well?
Thanks,
Marton








Take off the pump body. That is the thing with the 4 hyd lines coming out of it. Disconnect the 4 lines and unscrew the 4 screws holding the body to the reservoir.
Now, if your pump has the screw in check valves, your job is easy. Using an Allen wrench, unscrew the check valves on the outside of the pump--one on each side of the pump. The quick and dirty fix is to replace them in reverse order since the up check valve seems to fail first, and you really don't need the down check valve. The proper fix is to remove the pressed on valve cap (part just above the O ring) I grab it with a cushioned pliers and twist and pull. Be careful! Don't **** it up! you need it again. under the cap you will see the check valve and the remains of the small O ring. Go buy one of these O rings in Viton and replace it. Carefully press on the cap and replace the valve assembly in the pump. If you have the pump with valves held in by circlips, these valves are not serviceable. To the best of my knowledge, no one sells replacement valves. Contact RRitt here and see if you can buy a pump from him. He will probably be jumping in here soon anyway. Pumps are his specialty.
 
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