Procedure for changing trim oil

dozerII

Admiral
Joined
Oct 25, 2009
Messages
6,527
What is the procedure for changing the trim oil on a 72 Merc 120, with the black large body pump. I looked all throught the manual and can only find the bleeding procedure.
Thanks Glen
 

picklenjim

Chief Petty Officer
Joined
Mar 11, 2009
Messages
528
Re: Procedure for changing trim oil

Remove the pin anchoring the trim cylinders to the rear of the drive. Disconnect all the trim hoses connected to the cylinders (4). Place a large pan under the cylinders where the lines are connected. Pull the ram out all the way and then push it back in all the way for each cylinder. This will remove all the oil from the cylinders. Then run the pump up and down until the pump and lines are empty. Follow instructions for filling and bleeding.

CHECK THE RESERVOIR FREQUENTLY TO BE SURE YOU DON"T RUN IT EMPTY DURING BLEEDING!! It takes a lot to refill your cylinders when they are empty. Running it empty will get air in the lines. Don't be surprised it you have to refill it 4-5 times.
 

Alumarine

Captain
Joined
Feb 22, 2005
Messages
3,684
Re: Procedure for changing trim oil

To refill I use a lower end lube pump on a bottle of ATF.

Less messy than a funnel.
 

mikeneal

Senior Chief Petty Officer
Joined
Jan 28, 2004
Messages
710
Re: Procedure for changing trim oil

I have a volvo penta and got water in trim oil from leaking ram seal and I used oil change vacuum pump to empty the reservoir and re-filled and then cycled the trim system. Did this couple times until fluid stayed clear. Used cheapest ATF I could find for the intermediate "fills".
 

dozerII

Admiral
Joined
Oct 25, 2009
Messages
6,527
Re: Procedure for changing trim oil

Thanks for the replys, I will give the ideas a try. Marc c Lac Bu Bonnet many good memories from there, spent quite a few summers at a cabin across from Docs island. Learned to water ski and caught lots of nice pickeral there.
Glen
 

Alumarine

Captain
Joined
Feb 22, 2005
Messages
3,684
Re: Procedure for changing trim oil

Thanks for the replys, I will give the ideas a try. Marc c Lac Bu Bonnet many good memories from there, spent quite a few summers at a cabin across from Docs island. Learned to water ski and caught lots of nice pickeral there.
Glen

Good luck. Where's Docs island?
 

dozerII

Admiral
Joined
Oct 25, 2009
Messages
6,527
Re: Procedure for changing trim oil

Changed my trim oil this morning, used a few ideas from everyone. I was shopping at Canadiantire the other day and they had a syringe for mixing small amounts of two stroke oil and it worked perfectly. I disconnected the back ends of the cylinders and let them hang down, then sucked out the contents of the pump and then refilled it with clean 20/50. Cycled the trim up and down a couple times and sucked out the pump again anrefilled with clean oil. It works great now. ;)
 
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