Tilt Trim Problem

captainron19

Seaman
Joined
Feb 10, 2012
Messages
54
Started having a trouble with my 1989 Mariner 150 HP Tilt Trim

I have 2 sets of pistons. Smaller set takes engine up (assuming to the trim positions) - when they max out the single larger piston takes over and takes it to the tilt position.

Once my 2 smaller pistons max out I hear the larger single piston kick it but it will not take the engine up. If I do it via the controls on the engine itself and stand at the rear pulling up slightly on the lower unit it does raise. But as it sits if you touch the outboard slightly you can hear the engine starting to drop which it will eventually drop the larger piston almost completely until it rests weight on the 2 smaller pistons which will hold it fine.

I will be trailering the boat and my main concern is getting the engine high enough for when there is a boat ramp that may cause my prop to scrape. I did tow it home from where I purchased it without any problems but I am the sort of person that hates to see things half ***** fixed and I rather it be readily available if I need it.

I purchased the O Ring repair kit and with the help of a friend we removed the trim tilt pump/motor unit and removed the pin that had several o rings installed on it and replaced all o rings and we replaced the manual lowering screw. We bench tested and the piston extended and retracted just fine (also made sure plenty of fluid in reservoir) after re-installing on outboard, the same thing happened (main piston will not take up the engine from where the 2 smaller ones max out and the motor will begin to drop once any pressure it applied)

Am I missing anything else to possibly check? Thought of just bringing it to a Mariner shop for service but unsure on the cost for something like this to repair.
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,074
Re: Tilt Trim Problem

I would bleed the system, before you try anything else. Trim it all the way up and lock it up. Help it up if you need to. Now let is sit 5 minutes and then refill with PTT fluid. Repeat a few times. You may see air bubbles in the fluid that need to escape.
 

gwukena

Petty Officer 2nd Class
Joined
Apr 8, 2010
Messages
167
Re: Tilt Trim Problem

Did you reseal the tilt cyL, or only resealed the pump and manifold? I doubt bleeding is going to work, sounds like you need to reseal the tilt cyl
 

aussieflash

Lieutenant Junior Grade
Joined
Feb 5, 2011
Messages
1,004
Re: Tilt Trim Problem

If its not leaking,do as chris said.Tilt it up and LOCK it with lever,fill, then up down a few times,rest 5 min,fill and repeat.
If its leaking or bleeding does not fix, do as Gwukena said and rebuild Tilt ram.You will need pin wrench to remove cap and replace all O rings and seals.Wear your worst cloths.Good Luck Paul.
 

captainron19

Seaman
Joined
Feb 10, 2012
Messages
54
Re: Tilt Trim Problem

Well filled the resevoir and raised numerous times letting it sit for about 5 minutes each time and still nothing...... the weird thing is, once those 2 smaller pistons max out and the large piston attempts to take the engine the rest of the way up it will not go but if I take one hand on the lower part of the engine and give it a little assistance it goes up..... but once up, if I put any pressure on the engine, it starts to creep down but again the 2 smaller pistons hold it fine..... is it possible there is some sort of check valve in there that may be bad that send the fluid to the larger piston once the 2 smaller ones max out?
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,074
Re: Tilt Trim Problem

Ron, The piston seal on the tilt cylinder could be bad. I have not worked on that type of unit, but a lot of times the seal is simply an oring. See if you can get a rebuild kit. If it holds pressure on the trim cylinders, the check valves are probably working.
 

aussieflash

Lieutenant Junior Grade
Joined
Feb 5, 2011
Messages
1,004
Re: Tilt Trim Problem

Rebuild main ram(centre).
Ram has 6 O Rings and a few washers and cap assembly.Main ram has multiple check valves at base of piston which will require cleaning.Port trim rod also has a check valve.
(Well filled the resevoir and raised numerous times)......How many times did you re fill.If its still taking fluid its not going to bleed completely....refill....bleed....refill.....bleed till it can take NO MORE.
 
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