Alpha one trim system...gets stuck up after sitting up for a few hours

[nikon]

Well, don't know why it's doing it but on my alpha one gen II trim system after I'm sitting at the sand bar for a while (trimmed all the way up) and I goto leave the drive refuses to trim down. I have to get someone to stand and jump on the drive to get it to go down.

Once I get it down though it moves through it's whole range without issue. Just started happening 2 weeks ago.

The only thing I can think of is air in the lines, but I'm unsure of how I could've got air in the lines. Last summer I rebuilt both trim rams, the hydraulic pump and replaced the low side(down) pressure regulator. The system is filled with 10-30 and the oil is fairly clean..

Any ideas? I'll probably just flush the hell out of the system, but it would be nice to know what caused it.

 

[Bondo]

Re: Alpha one trim system...gets stuck up after sitting up for a few hours

Any ideas? I'll probably just flush the hell out of the system, but it would be nice to know what caused it.

Ayuh,... When ya put it Full Up, 'n it crowds, tap it down abit to unload the overload pressure...
And,...
Have a look at the end-caps,...
Corrosion, 'n wildlife can cause 'em to Bind on the ram...

 

[nikon]

Re: Alpha one trim system...gets stuck up after sitting up for a few hours

I always bump it down after it stops up....There's no corrosion in the caps however the bushings do need to be replaced. I'll start with those and go from there.

 

[nikon]

Re: Alpha one trim system...gets stuck up after sitting up for a few hours

Just re-read your post, I thought you were talking about the bushings attaching the ram to the stern drive so I of course ordered some...

I just rebuilt the rams the end caps are clean....

Any other ideas? I'll bleed the system this weekend but wanna try and prevent it from happening again.

And just to add some more confusion to the problem, I store the boat with the drive half up and it goes down from the position after sitting for a week no problem.....it's just the full up/almost full up position.

 

[Bayliner1952]

Re: Alpha one trim system...gets stuck up after sitting up for a few hours

Can you Post the procedure for flushing the trim fliud? My alpha 1 GenII has some hickups sometimes and I think it could use a flush.

Thanks,
Nate

 

[nikon]

Re: Alpha one trim system...gets stuck up after sitting up for a few hours

http://www.mediafire.com/?6k49y3ke97o3630

Thats the service manual for the whole drive, the flushing procedure is in there.

Just fyi, flushing the trim system didn't fix my problem...even if my drive is only 3/4 way up for a few hours it gets stuck up. In fact when trying to lower the drive we say air bubbles and a bit of oil come out the end of the ram. So I have a blockage that only rears its head when the drive is left up....My guess is a stuck check valve somewhere in the trim system, what I'm trying to figure out now.

 

[vandentr]

Re: Alpha one trim system...gets stuck up after sitting up for a few hours

Could it be that one of the shafts are bent? It doesn't take take much to screw up their operation...

-TVB

 

[nikon]

Re: Alpha one trim system...gets stuck up after sitting up for a few hours

No, once I get the drive moving it starts operating normally....that's why I'm guessing a check valve is getting stuck, since the drive is up it is leaving pressure on that check valve. Once It breaks free its back to normal....don't know what else it could be.