Hydraulics question

[jam39vw995]

Hi.<br /><br />Thanks Bondo for the flare wrench size, it was a 3/8. This is a merc 165 and it's newer than I thought so it's probably an alpha drive.<br />Well, I attempted to get the hydros working today but didn't succeed.<br />I bled the system as per the shop manual. The leg goes up great but down it goes about 1/2 way and then the pump increases in speed and it stops. I cycled the leg many many times, adding oil each time but I still had to push the leg down for the last 1/2.<br />I'm pretty sure I had one of the lines on backwards on one of the rams and I corrected that, then things seeemed to improve except trying to get the leg down.<br /><br />Any ideas what would be causing the leg to go up well and then only 1/2 way down well, then stop?<br /><br />Thanks<br /><br />Jeff

 

[Bondo]

Re: Hydraulics question

Jeff, A Couple of Thoughts......<br /><br />You Do have a Model 1, or "R" drive...... Alpha1s, or "MR" came out in 1984,+ Don't have the "Eye" in the top cap.......<br /><br />Did you disconnect the ends of the Rams....<br />Will the rams run their Full Stroke, without the outdrive Attached ????<br />Will the Outdrive Drop All the way Down under it's own Weight, Without the rams attached ????<br />The Merc. powertrim system relies on the weight of the drive to lower... That's why the pump speeds up after you bottom out, or the pump loads up when the top limit is reached.....<br />You should also have a reverse-lock valve mounted on the inside of the transom.... This keeps the outdrive from Jumping Up, when backing the boat.... So, In Theory, you can't trim up in reverse....<br /><br />I Suspect you've got Either the drive, or the rams Binding up on the down stroke.... <br />Disconnect them,+ See Which it Is.....

 

[jam39vw995]

Re: Hydraulics question

Thanks Bondo, I'm copying your reply. It does make the post longer but imo easier to follow. I wish the post reply function did this for you.<br /><br />~You Do have a Model 1, or "R" drive...... ~Alpha1s, or "MR" came out in 1984,+ Don't have ~the "Eye" in the top cap.......<br /><br />I'm pretty sure it's an alpha 1, I looked on http://www.mercstuff.com/drive_id.htm and it's the second one down.<br /><br />~Did you disconnect the ends of the Rams....<br />~Will the rams run their Full Stroke, without ~the outdrive Attached ????<br /><br />I did disconnect them to bleed.<br />But I didn't try the down stroke. The procedure was a little confusing so I did my best to understand it.<br /><br />~Will the Outdrive Drop All the way Down under ~it's own Weight, Without the rams attached ????<br /><br />Yes.<br /><br />Going up is perfect and fast. Down goes fast from the top to about 1/2 way and then the pump increases in speed and the leg stops moving unless you push it down. When you push it down the pump resumes it's normal sound. I suspect there is still air in the system or the pump is sucking air from somewhere. I did not see any visible leaks.<br /><br />Thanks<br /><br />Jeff

 

[Bondo]

Re: Hydraulics question

I think you're headed the right way.....<br />Have someone run the pump for you + Bleed them at the bottom of the Rams......<br />You'll want Plenty of Rags.... <br />The Fitting you're Bleeding is the 1s with all the Pressure....<br /><br />Ya, It looks like you have an Alpha1.... Your earlier post lead me to think you had a Mod.1...

 

[jam39vw995]

Re: Hydraulics question

Thanks Bondo,<br /><br />Which line do I disconnect? The fore or aft one? Do I disconnect both sides? Then run the pump in the up until I see clear fluid and no bubbles?<br /><br />Yes, an earlier post of mine may have mentioned a drive with the loop on the top cover. It was my confusion between the one in the boat and the free 470 with the mod.1 outdrive.<br /><br />thanks<br /><br />Jeff

 

[Bondo]

Re: Hydraulics question

The fore-end lines Should be the "Up" lines....<br />The Aft, Down lines.....