Yamaha HPDI tilt and trim driving me nuts

[Wannabetoo]

Started having issues with my tilt and trim on my 2003 250 HPDI – VZ250 TLRB. The trim would drag and sometimes hang when it switched over to the tilt and occasionally would not come down and I’d have to use the manual release to get it back down.

I figure it’s a leak on one or more of the seals, although I found no fluid. I then repeatedly attempted to add fluid just to get it to work properly or at least better until I could address it fully. Many attempts and I could not make it work much better. As “luck” would have it, trashed my lower unit thereafter and bought a blown hpdi and swapped the lowers. Also swapped the trim unit (call it trim 2) and it worked property for a few months then started doing about the same as trim 1. Meanwhile I put trim 1 in the shop and limped along adding fluid to trim 2. Trim 2 will take fluid and improve, but the process is tedious and not long lasting.

Shop puts seals in trim 1 and I installed. Motor works great on the bench with full travel. On the boat, won’t attempt to lift or lower. Back to shop.

This time, they rebuild the pump. Installed last night. From the tilt lock it won’t do anything. Turn the release screw and lower till it touches trim rams. Still nothing. Lower all the way and now the motor will slowly trim about 2” of travel and gives up. Hit down and it won’t move. Hit up again, no movement, then down and it will trim all the way tucked and then repeat traveling 2”, hang and not move. A quick up, then back down and it will tuck.

OK, so the shop told me to try trim 1 and make sure it will work before I pay for the repairs…which was nice, but now they’ve made two attempts and rebuild a pump (who knows what that will cost and I was pretty sure that is not the problem, plus they could have robbed the pump from trim 2 if they would have checked with me.) and I still don’t have a trim that works right.

I’m convinced the problem is about $8 in parts and is some check valve or relief valve or something along those lines.

Any advice?

Wannabe...

[wbrown]

How are you filling the fluid and bleeding the system?

[Wannabetoo]

Raise motor to tilt lock. Lee sit for a day. Burp fill cap. Shot as much check fliyud as I can cover with finger replace cap. Lower motor with manual release screw. Close manual relief trim up to lock. Repeat twice more but letting sit for only a minute or two.

[wbrown]

After fixing seals on my units and having to refill the whole system, I've tried other methods of filling and bleeding the fluid. The whole fill, then lower with manual screw, then raise manually and repeat, etc and so on and nothing has worked like this following method for me:

If you have the trim cylinder caps off, pour as much fluid into the system as you can. (This is obviously done when you're replacing seals and have drained the system of fluid.)
Now raise the motor up and flip the stops down to hold it.
Unscrew the cap, and using a syringe, put as much fluid in the system as it will hold before it starts pouring out the fill hole.
Fill your syringe again, and this time press and hold the trim up button on the side of the outboard and WHILE doing so, squirt more fluid into the fill hole with the syringe. When you run out of fluid in the syringe, take your finger off of the trim up button.
Now repeat the last step again and again. When the system starts getting close to full, the outboard will start lifting up off of the stops. This is fine. Keep repeating the steps until the outboard goes all the way up AND fluid starts pouring out of the fill hole.
Once it does this, and while the outboard is still all the way up, let the excess fluid drain out of the fill hole. Screw the cap back on.
Trim the motor ALL the way down and ALL the way back up several times.
Stop at the very top, open the cap and you'll hear air rush out.
Repeat the syringe fill process and the trim down and up a few times until it will take no more fluid.

I have found that filling the unit other ways still sometimes leaves air pockets in the system that are hard to get out. When you press the up button on the trim it sucks that fluid down through the system, so using the syringe and adding more at the same time helps ensure the system is sucking fluid in and filling the entire system while forcing air to the top.

It's possible something else is going on like a check valve or motor problem, but I would make sure there's zero air in the system first.

[Invader186S]

This method has always worked for me:

http://www.bbcboards.net/showthread.php?t=32749

[Wannabetoo]

With some help I was able to turn the release acre and manually lift to stow on the lock last night. I've read through yall's post and will try your method with trim unit 1. I suppose it's possible that there is air in the system since the unit was delivered to the dealer off the boat. Without a load, they had no way to test it before I picked it up. Also, without weight there would be no way to bleed it right according to your methods. One thing I did notice. On trim #1 before it was worked on and now on trim 2 when I turned the release screw, there was a hard stop. Maybe 1-1.5 turns. Now on trim 2, there is no stop. I actually turned it to the point that fluid started to ooze out. Luckily, I didn't back it out all the way. That would have been a mess.

Ill report back on the progress after I fool with it this weekend.

Thanks for for the help.

Wannabe....

[Rich Z]

Before you begin the bleed process ensure the boat is nose down or parked down hill. The tilt/trim unit must be verdical to completely release all air. With boat sitting level the unit is always at slight angle!!!

[Wild Heethen]

Related question-on my 2002 HPDI 200, when trimmed out, it will slowly over time ease itself down all the way. No leaks of any kind. Could this be a need to bleed issue or is it something internal? Thanks.

[bgibson]

Related question-on my 2002 HPDI 200, when trimmed out, it will slowly over time ease itself down all the way. No leaks of any kind. Could this be a need to bleed issue or is it something internal? Thanks.

Check manual release valve first to make sure its all the way closed. If it is then you have an internal leak.