power tilt will not go down

[dougmn]

the power tilt will not go down on my 1996 evinrude. it will tilt all the way up but will not go down what is wrong?<br />it makes a screatching noise when you hit the down button and will not go down. any help would be good thanks!

 

[JB]

Re: power tilt will not go down

Howdy, Doug.<br /><br />Welcome aboard. <br /><br />Hydraulic pumps screech when they cavitate or when they try to pump air. <br /><br />I suspect yours is trying to pump air. When fluid is low they go up and stay there so you can get at the reservior to top it off.<br /><br />Large slotted plug on the cylinder. Remove it and add hydraulic fluid to top it off.<br /><br />Your Service Manual will describe what to do and show you pictures. . . .WHAT? You don't have a manual? Well, fix that first.<br /><br />Good luck.

 

[Basscat 1]

Re: power tilt will not go down

JB, this brings up an interesting question. Why does the book say to raise the motor in the full up postion to fill the hydraulic fluid? To me this goes against everything I have ever been taught about hydraulics. Any hydraulic system that I have ever worked on or serviced which includes Army Tanks, we allways lower or retract the cylinder to return all of the oil back into the reservoir, or in this case the pump, and then fill it with oil. This prevents to much fluid from being added so that when the cylinder retracts, it wont blow something up. Does this make sense? I am just curious as to why the book says to add fluid this way.<br />Thanks.

 

[Jcrain]

Re: power tilt will not go down

I'll take a stab at this, or at least part of this. On a hydraulic jack you use fluid to raise it and you only have fluid on ONE side of the piston. To lower the jack, you crack open the valve and allow the fluid to return to the resivior. The weight on the jack "pushes" the fluid back. On a tnt, The pump is a bi-directional motor that can pumr to either side of the piston.Depending on which way you push the switch, it directs the fluid to one side of the piston to raise, or to the other to lower. Since, it effect, the piston has the same volume of fluid in it, whether full up, full down or anywhere in between, it doesn't require to be bottomed out to service. The reason for fluid being on both sides of the piston is to give it a hydraulic "lock" to hold it at the position you trim it to........ WOW, way too much coffee this morning....

 

[Basscat 1]

Re: power tilt will not go down

That makes sense. If fluid is the same volume on both sides of the cylinder, then why would it make a difference if you fill it in the up or down position? Just something to ponder.

 

[Dave Abrahamson]

Re: power tilt will not go down

Can't get to it,(the fill hole),in the down position.<br />Mine is stuck up on just the trim rams......still.<br /><br />Dave

 

[Basscat 1]

Re: power tilt will not go down

Can't get to it,(the fill hole),in the down position.

I guess it depends on the type of tilt and trim unit you have. My fill plug is on the outside, so it doesnt matter if its all the way up or down.

 

[dougmn]

Re: power tilt will not go down

I checked the t&t fluid level and it is full. now what? Thanks Dougmn.

 

[Jcrain]

Re: power tilt will not go down

You should have a manual release screw. Have you tried that? Have somebody hold the motor and release itusing the manual release screw and let the engine all the way down. Tighten the release, then hit the up switch.

 

[Jcrain]

Re: power tilt will not go down

Also, check that the "trailering lock" isn't engaged. That'll sneak in there and bite you sometimes.....

 

[dougmn]

Re: power tilt will not go down

The trailering lock is not in place. where is the release screw.thanks,Doug

 

[Cricket Too]

Re: power tilt will not go down

It's on the tilt cylinder, it should be marked by a sticker or something, but that may be gone at this point, it's a big screw, a flathead I think, loosen it and it will release the pressure in the cylinder.

 

[Basscat 1]

Re: power tilt will not go down

Or just crack the line going into the trim motor.

 

[Tempest16]

Re: power tilt will not go down

dougmn, I had this same problem last year, my trim would go up but not down. So I filled the fluid up, hit the release valve and still, up but not down. Problems can occur when air bubbles are caught in your cylinders, but I highly doubt thats the problem, even with air bubbles you get some movement down. Here is what I did.<br /><br />Removed my entire power trim and tilt unit from the engine, then, slowly and carefully, I took the pump off the unit to check the valves. (You will need a service manual to do this properly) It turned out I had a chunk of rubber (who knows how it got in there) lodged in the valve of the pump which would pump the fluid out and in turn, lower the engine. After removing the rubber, I put it all back together, tightened the release valve and presto, worked like new again. So if all else fails, give'er a shot.

 

[dougmn]

Re: power tilt will not go down

Temp 16 I think i might have a similar problem, where did you get your manual,thanks.Dougmn

 

[JB]

Re: power tilt will not go down

Aftermarket manuals here, Doug: http://www.boatmotors.com/manuals.html <br /><br />There are several places that offer reprints of OEM Manuals. One is kencook.com.<br /><br />Good luck.

 

[rodbolt]

Re: power tilt will not go down

hello<br /> if its the showa style pump assy its the same as the yamaha as far as the hydraulic circuits go. with no trim down I would suspect, after checking the manual release screw and oil level that the pump body has a bad up main. bad up check valve a cloged down intake screen or a bad down relief assy. BRP does not offer much in the repair area for the showa assy. but the cost of the pump assy is half what yam gets for theirs. same as the trim motor. 659 from yam vs about 190 from BRP.

 

[dougmn]

Re: power tilt will not go down

Took yhe pump off the the t&t unit,when I released the last screw a small shot of fluid under pressure came out.I reinstalled the pump and it now raises and lowers just fine. Now the problem is in the up postion the motor will visibly settle all the way down in a minute or two.Thanks.Doug

 

[Basscat 1]

Re: power tilt will not go down

Are there any visible oil leaks? Check that the manual relief valve is fully closed. Check relief valve in tilt cyl.<br />If those check ok, then possibly your pump check valve is defective or has trash in it.<br /><br />Since I last posted on this thread, I bought an OMC service Manual that was for my particular boat motor. I already had an aftermarket service manual, but the factory one explains in more detail about the tilt and trim system including breakdown diagrams and pictures. I now understand more clearly how this system functions.

 

[dougmn]

Re: power tilt will not go down

Basscat 1 It was full of fluid,no leaks.The manual valve is closed.Where is the relief valve in the tilt cyl?Is it under the snap ring for the manual relief valve?The pump ball bearings that I can see move freely,I'm afraid to take the pump apart without a good manual.A fellow on here suggested a site that had a drawing of the internals but it was not real clear on my computer.Ihave a johnson,evinrde factory manual but it has nothing on the internals for the T&T.Thanks,Doug