Trim Cylinders Fully Extended - Won't Retract

[MercMonster]

I just got the point where I was ready to test the trim getting it set and all. I had removed the trim connector to replace both upper hydraulic cables inside the boat. When I removed the connector and installed the new hoses, I'm pretty sure without a doubt, there's a lot of air in the system. Refilled the pump with fluid and used the trailer switch and both of the arms fully extended. Was going to try the in - out method as they are "supposed" to be self bleeding, but lots of air in the line apparently. Problem is, neither one will retract. Motor runs when I hit the switch, but the arms won't retract So, I'm thinking there is air in there somewhere. I check the manual to find out how to purge air out of the system. Says to fully retract the arms, open the aft port hose, then fully extend, OK, I can't do this, arms won't retract. Would I open the forward line on the trim cylinders first to try to purge the air out that way first?? My thought was since I would have to start in reverse of what the manual suggests, this would be my open option. Is there an easier way to purge the air? How do I get the air out of my trim lines?

 

[tommays]

Re: Trim Cylinders Fully Extended - Won't Retract

If there all the way OUT then get your BIG friend to stand on the drive and this should get them moveing

Some grease on the shafts will also help lube things up a bit on the way down




Tommays

 

[MercMonster]

Re: Trim Cylinders Fully Extended - Won't Retract

I was afraid I might blow a hose, or something worse, doing something like that. Should I unscrew any of the trim cylinder hoses and then push them back in?? If so, which ones? aft, forward or both??

 

[backwater dawg]

Re: Trim Cylinders Fully Extended - Won't Retract

You are probably out a little to far---I would do as the last guy said and stand gently no it to start it going down--good luck

 

[MercMonster]

Re: Trim Cylinders Fully Extended - Won't Retract

Thanks, I'll run and go try it!

 

[MercMonster]

Re: Trim Cylinders Fully Extended - Won't Retract

Well, I didn't have the drive on and trying to do it as suggested wasn't going to work without the drive, so I mounted & dry-fitted the drive snug and tried it with just the weight of the drive, no dice. Then I stood on the drive: I don't get enough meat and potatoes in my meals to be a big man so I had to bounce a little and it did retract, but when extended again by the controls and tried to retract, no dice. The reservoir was kept filled by my friend who was also at the controls, so that wasn't part of the problem. Even without the drive, it acted like it wanted to retract, but just didn't have the umph to do it. Any other suggestions? Is this still indicating more air in the system? The Merc manual doesn't even cover this particular problem in the manual troubleshooting section.

 

[Scarebird]

Re: Trim Cylinders Fully Extended - Won't Retract

I had this a month ago- the shafts were frozen to the cylinder ends. Had to pop loose in a press, then sand out lightly with 800 ggrit, works smooth now.

 

[Bondo]

Re: Trim Cylinders Fully Extended - Won't Retract

Ayuh,.....

Trim Pumps in boat are generally High pressure Up,+ Low pressure Down.........
They rely on Gravity,+ Thrush to Lower the drive.....

Did the rams move Easily in,+ out when you had the Lines off them,..??..??.....

 

[MercMonster]

Re: Trim Cylinders Fully Extended - Won't Retract

The trim IN and Out both worked fine just before replacing the two lines. After searching here through some old posts on the subject, I found one where there was a similar problem. The trim was fully extended when I started out with this, so that's when I topped the fluid and replaced the bolt. I'm maybe thinking this is wherein my problem lies. Will try to go over tomorrow and remove the bolt & remove fluid to correct level. I'm hoping this will solve it...

Did the rams move Easily in,+ out when you had the Lines off them,..??..??.....

Yeah, they both moved flawlessly.

 

[ziggy]

Re: Trim Cylinders Fully Extended - Won't Retract

The trim was fully extended when I started out with this, so that's when I topped the fluid and replaced the bolt. I'm maybe thinking this is wherein my problem lies. Will try to go over tomorrow and remove the bolt & remove fluid to correct level. I'm hoping this will solve it...

i think yer onto a good idea..........i think ya are are way overfull......

 

[MercMonster]

Re: Trim Cylinders Fully Extended - Won't Retract

Well, the drive was all the way up, took the bolt out of the reservoir, tried to trim down and it went down VERY slow, like a MM a second so had a neighbor friend (chick) bounce a little on the drive to get it all the way down to purge any air (was accused by SO of just trying to see bouncing B**bs) That was probably the only benefit to this whole situation I still can't get this thing to go down on its own accord. I'm thinking if the weight of the drive weren't on it, it would take an hour for the cylinders to fully retract. Am I to still suspect air in the lines or cylinders somewhere or am I at another point in this battle. The cylinders still fully extend like they are running on an brand new pump. Takes about 4-5 seconds. What can I check next?

 

[ziggy]

Re: Trim Cylinders Fully Extended - Won't Retract

out of merc service manual #2.....

power trim malfunction, hydraulic, will not return completely to down position or returns part way with jerky motion......

possible causes...
air in system
internal cylinder(s) leaks
internal resistance in cylinders
hoses reversed on one cylinder only


mechanical causes.......drive houseing interference with gimbal ring

 

[coastalcruiser]

Re: Trim Cylinders Fully Extended - Won't Retract

Do you have enough oil in the pump?
I use the filler pump that I have for leg noticed it also sqrews into the trim pump

 

[wire2]

Re: Trim Cylinders Fully Extended - Won't Retract

>>had a neighbor friend (chick) bounce a little on the drive to get it all the way down to purge any air (was accused by SO of just trying to see bouncing B**bs)<<

Get that camera out and post!

How about undoing both lines from the pump, place the ends in a clean jar ? full of fluid, then push the cylinder(s) in by hand.

It should deposit oil from the extend side, and draw from the retract side, purging all the air in the process. If need be, do the same with individual cylinder lines in pairs.

If it resists travel, you'll know you have a mechanical bind somewhere.

 

[MercMonster]

Re: Trim Cylinders Fully Extended - Won't Retract

Get that camera out and post!

You really are trying to get me in trouble aren't you??

I did what I could with this thing and never could get to the root of the problem. Have noticed now that the drive is bleeding down VERY slowly after leaving for several days. I guess I've got some problems with the pump/seals. Will live with it for the rest of the season and hope Santa brings me a new trim pump/motor for Christmas, unless some elves have a better solution. Guess I'll have to just stand on it after launching and get her all the way down and then do the same thing every time I come off plane. Boy, does that sound like fun Will make sure the keys are in my pocket when trimming down every time so I don't slip and lose some toes, or a foot.... She'll be lucky to dip her hull in water before the season is over. The fuel pump on the "new" engine isn't pumping any fuel so I'll be putting on the pump from the old motor tomorrow, which I know was working before. Gasket $1.99. Nobody told me boating was gonna be so much fun, and I haven't even had her in the water yet