Power Trim Cylinder leak

rderenzy

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While thinking it was my braided cables, I noticed a water bubble on the seal of my power trim cyclinder
:(
a 400$ part

​any idea what estimated shop time for hourly fix is? 2 hour job? 1 hour job? etc
​trying to set cost expectations
 

tpenfield

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It is a 30 minute job that you will be charged 4 hours for :D

Feel free to replace it yourself.
 

rderenzy

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4 hours, come on, I heard the alpha drives are easy to swap them out

not sure if I can - the hydraulics scare me and if I have to bleed the lines and etc. i'm not realy sure what i'm doing.

​although I just did rip and replace the circulating water pump on the front of the engine - *flex* ;)

​1997 4.3 merc - alpha gen2
 

rderenzy

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you got any go to spots on the web here to find step by step instructions for installs such as this one?
 

rderenzy

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what the heck - why weren't those lines pressurized? and why didn't trim fluid shoot and leak all over the place?
​if that is al it is then wow, easy peasy.
​however. i'm going to need to do more - i'll have to bleed or flush all of the fluid out, otherwise i'm going to blow the seal again
 

tpenfield

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The lines are not pressurized. . . You can prime the cylinder with the oil if you want.

Basically, the system primes and purges air after about 10 up/down cycles.
 

tpenfield

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No . . . only the weight of the outdrive creates the pressure. When you support the outdrive before removing the trim cylinder there is no pressure.

The lines will bleed slowly, and all you need to do is add fluid to the reservoir as you cycle the trim to prime and purge the hydraulics.
 
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achris

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Line pressure is created by load on the cylinders. No load, no pressure. The only leakage while the cylinder is open will be due to gravity.

Priming and bleeding is done by using the pump. Just run it up and down a few times.

Chris. ...
 

rderenzy

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thanks to you both, but now i'm more confused
​do I need to hold up the drive and prop it up? in the video, he just rips off the one arm no problem.

​i'm only replacing one, the portside one
​If I rip off that cylinder, taking all the lines off on just one side, will that be enough to bleed the lines? or will I need to take both cyclinders off?

​thank you so much
 

achris

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Don't rip anything off. Remove it gently and with care. And you're not listening. Bleeding of air is done by running the cylinders fully up and fully down a few times. You only need to remove the cylinder you need to repair. And I don't even do that. I just disconnect the aft end, support it up and loosen of the end cap. Then pull the piston and rod out and work on just that. Once I have all the new seals in, just put the piston and rod back in the cylinder. Job done.

Chris. ..
 

rderenzy

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thanks and sorry achris

​i'm comfortable removing and replacing the cylinder, I get that part. and the video makes it easy to follow.
I also understand, that i can bleed the lines and get the air out by moving it up and down, once fluid start coming out, its ready to be connected (thus air out)

​where this took a wrong turn is that i'm looking to flush the entire fluid - not just the air.
​there is a lot of water in the system and I want to flush it all

​I think the question is, once I remove the bad cylinder - am I able to flush the system with only the left side detached (I would think I have to detach both sides as I don't want one arm doing all the lifting up and down - along with flushing the other side)
that is what i'm confused on
 

achris

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If one side is disconnected, then the remaining cylinder is not going to move. The fluid must push against something to produce pressure and if one line is open, no pressure. And even if you close of the open line, the remaining cylinder is more than capable of lifting the drive without any damage at all. One of the beauties of hydraulics, it can't lift more than it's capable of. You can't overload it.
 

Bondo

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​I think the question is, once I remove the bad cylinder - am I able to flush the system with only the left side detached

Ayuh,.... Hydraulically speakin', both sides are Common, at the manifold block under the transom housin',....
 

rderenzy

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If one side is disconnected, then the remaining cylinder is not going to move. The fluid must push against something to produce pressure and if one line is open, no pressure. And even if you close of the open line, the remaining cylinder is more than capable of lifting the drive without any damage at all. One of the beauties of hydraulics, it can't lift more than it's capable of. You can't overload it.

that is great info, thank you
​last question, so with the one cylinder and houses disconnected only on one side, and I run the system to flush it - will it eventually flush the other side as well? (even though one side is fully connected) or to full flush, i'll need to disconnect all?

​last thing I want to do is drop money on trim fluid and only flush 75%, only to have that new fluid compromised again

thanks!
 
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