Mercury 225 Trim Pump Oil Capacity

[lewis_is_bassin]

By chance does anyone know the oil capacity of a trim pump on an 01 Mercury 225 optimax? Just replace a leaky cap on one of the side cylinders (not the main cylinder). Anyhow, not much oil came out when I drained the system. I took both caps off and drained the entire system, to have a fresh start. I've now added a quart of new oil and the system is still not full.

I did a google search, with no luck. Any help is greatly appreciated.

[Mike Cork]

I don't know exactly how much it takes to fill a system up, however I have serviced mine several times because of a small cylinder leak.

Lift the motor as much as possible to fully extend the actuators and then fill to the edge of the fill port. I then cycle the system several times and top it off. Seems to always work for me.

[lewis_is_bassin]

Thanks, Mike.

I figured out my problem. I had air in the system that kept making the oil prematurely spill. After watching a few YouTube videos, I lowered my trailer jack all the way down, slowly opened the fill cap (to allow any trapped air out) once done, I fully opened the cap. I then topped off the fluid and bingo! It seems to be working much better now. I'd say it too a little over a quart. Getting that little bit of air out really helped. Thought I'd share in case anyone was having the same issue.

Man, YouTube has a video on everything, Ha!

[Mike Cork]

Thank you for the follow up. Hydraulics and air don't get along, good tip.