The oil should be visible in the filler neck of your NO.44 hydraulic control on your D4 7U. If you are a "paying" member and can access the ACMOC library please read the Operation and Maintenance Instructions(OMI) for the NO. 44 hydraulic control.
Craig
If you want your own copies I found these on eBay. You really need both, they will save you time & money & heartaches.
Craig
D4 7U:
https://www.ebay.com/itm/404441554546
NO. 44 hydraulic control:
https://www.ebay.com/itm/375373987442
"i reject your reality and substitute my own" - adam savage. i suspect my final words maybe "well shit, that didnt work"
instead of perfection some times we just have to accept practicality
oil should be just visible at the bottom of the filler neck. any more and it will overflow as the oil expands with heat.
I have my own question about correct oil level/amounts for a #44 unit with the surge tank. What is the proper amount? Someone said only 1/4 full, here I run them about 1/2 full. I have seen some folks get a bath from too much. Also, is the system supposed to be able to breathe? Factory cap has no obvious means of ventilation. Thoughts? TIA JM