Trim issues for my Alpha Sterndrive

[RedneckCatter]

Hello hello. Its been and still is a long winter here in iowa. Ita been a while since ive posted questions but that because most my answers are already here. But time to ask. Been hours searching.

I have a Merc 470. MCM470.

I was working on the trim pump. Everything on it is working but all information i find is the newer rams that have one of the hydraulic lines going under and to the end of the ram. My cylinders have both down and up lines right next to each other. Which one is the out/up and in/down. The one closest the boat or the one an inch further away.

They are working up and down now but the in button lowers it and the up/out button raises it. I have wired the pump and switches as per the manuals. Except i bypassed the trip limit switches by jumpering the purple/wht wire to the blue/wht one. The limit switch wiring is toasted. So my button that just says UP does nothing im assuming because of that.

If i swap the lines from what i have them now thinking that would make the buttons work propperly both solenoids when activated raise the motor. Not sure if it would do that because of a bad cylinder or not. Air in the lines or maybe because i bypassed the limit switch. Im New to hydraulics. My trim motor is the dual solenoid Prestolite Power Trim Pump as from Manual #6.

Im also in the process of trying to figure out why it slowly drops from the up position like theres a leak. Was thinking a bad cylinder but wanted to make sure it was all setup correct first.

Thanks guys. If anyone has an answer im sure it will come here.

 

[RedneckCatter]

Thanks for any advice i could get.

 

[GA_Boater]

I think it's working right. IN lowers the the drive IN to the water and UP/OUT raises the drive OUT of the water. The UP is depressed at the same time as UP/OUT to tilt the drive past the trim limit switch. Since you bypassed the limit switch, the UP has the same function as UP & UP/OUT now - the drive can be raised past the max trim position. So be careful you don't over trim the drive.

This is from my long ago memory, so I could be foggy. The droop is another problem that I really can't help with.

 

[achris]

Hello hello. Its been and still is a long winter here in iowa. Ita been a while since ive posted questions but that because most my answers are already here. But time to ask. Been hours searching.

I have a Merc 470. MCM470.

I was working on the trim pump. Everything on it is working but all information i find is the newer rams that have one of the hydraulic lines going under and to the end of the ram. My cylinders have both down and up lines right next to each other. Which one is the out/up and in/down. The one closest the boat or the one an inch further away.

They are working up and down now but the in button lowers it and the up/out button raises it.

That's exactly how it should work if you have bypassed the trim limit switch (which is a VERY common fix for a bad limit switch or its wiring).

I have wired the pump and switches as per the manuals. Except i bypassed the trip limit switches by jumpering the purple/wht wire to the blue/wht one. The limit switch wiring is toasted. So my button that just says UP does nothing im assuming because of that.

The way the system should work when the limit switch is working is as follows...

IN/DOWN. Lowers the drive from all the way UP to all the way DOWN.
OUT/UP. Raises the drive from all the way DOWN to the limit of travel determined by the limit switch. This is to keep the drive within the confines of the gimbal ring when the engine is running. Also known as the 'trim range'.
UP. Pressed in conjunction with the OUT/UP button it's used to raise the drive from the limit switch upper extent to the full UP position for trailering. On later trim button panels is called "Trailer".

When you bypass the limit switch the UP/OUT switch will run the drive all the way UP, and the UP switch will do nothing.... Just the way you're seeing it

If i swap the lines from what i have them now thinking that would make the buttons work properly both solenoids when activated raise the motor. Not sure if it would do that because of a bad cylinder or not. Air in the lines or maybe because i bypassed the limit switch. Im New to hydraulics. My trim motor is the dual solenoid Prestolite Power Trim Pump as from Manual #6.

I've never tried running the pump with the lines on backwards... You're breaking new ground.

Im also in the process of trying to figure out why it slowly drops from the up position like theres a leak. Was thinking a bad cylinder but wanted to make sure it was all setup correct first.

2 reasons the drive will drop if there's no obvious oil leaks. 1) internal leak in the cylinders, or 2) internal leak in the valves in the control block on the base of the trim pump.

Please delete.. Computer issue never showed it posted and i duped it.

All duplicates deleted... :thumb:

 

[RedneckCatter]

Thanks. Ya i have bypassed others before. I always watch the drive level when raising it. Im going to grease the cylindars, raise and lower while standing on it, grease again a few times. When bleeding the lines to i need to keep the fill screw out or will that only intruduce air as im trying to remove it?

 

[achris]

If my memory is right, the 'front' lines (the ones closest to the bow of the boat) on the little manifold under the gimbal housing are the UP lines.

 

[RedneckCatter]

Thank you for the confirmations and some info. Its starting to snow and will be 19 degrees soon. I have a couple extra cylinders given to me on hand. No visible leaks outside the boat. Still need to clean good around the pump lines and check for small leaks. If there isnt ill either replace a ram at a time and/or rebuild the ones i have. The pump unit that is in the boat was one also just given to me. I tested the one i took out after knowing better about them and it works good too at least i got a spare complete pump unit. Thinking ill buy two extra lines and test the other cylindars one at a time from inside the warmth of my house lol

 

[RedneckCatter]

I do have one other question while its on my mind. I been reading some about a reverse lock.. Since i removed the pump from all other sources like ignition and limit switches is there anything i need to worry about when reversing the boat? Dont want to damage stuff. Heard about people blowing cylindars.