Mercruiser Alpha One gear oil level

[QBhoy]

All
With the new boat, it's the first time I've had the remote gear oil header tank and alarm system.
Question is, after changing the gear oil in the usual bottom to top fashion (mercruiser) until out the the vent screw, I then tightened up the vent screw and then filled the header tank, almost, to allow the oil to naturally drop into the space surely left over above the vent screw.
After running for a few hours, the level has dropped, but continues to do so. Not quite at the low level line yet, but almost. How much extra is normal ? It doesn't appear to be leaking. I estimate around 1.7l has been put in so far. Is this normal ?
Thanks

 

[dingdongs]

If you wasnt losing oil b4 the change shouldnt see why anything shoud change.just top it off once again and check its not losing anymore through the prop or seals wher the ujs are hardest to see as drive requires pulling from the gimbal but only if you cant see if its leaking from anywhere else

 

[mlines]

I used to fill mine completely from the bottom upwards (ie. even the header tank) however it would still drop for a couple of weeks as the last bits of air came out the system

 

[QBhoy]

Thanks all, I'll give it a top up, once it stops dropping and keep a close eye.
Ta

 

[Anthony]

I used to fill mine completely from the bottom upwards (ie. even the header tank) however it would still drop for a couple of weeks as the last bits of air came out the system

This is the documented way to do it, as it pushes the air up out the line into the header tank. If you haver twins then make sure the person monitoring the tank level in the engine room knows which tank to look at as you fill her up from outside; no need to ask me how I know (it was like the Only Fools and Horses chandalier dropping moment...).

Ants