So, I'm working on a 644E loader, the spec seems to say 30 gallons for hydraulic system capacity, 6 gallons each axle and 4 gallons for the trans, numbers rounded off. So with the axles filled and hydraulic system refilled, after splitting, overhauling the center pin, overhauling the steering cylinders, replacing a handful of lines and rebuilding the brake pump. So there wasn't much fluid left in the system, cleaned all the main lines to make sure there wasn't any debris. After filling the hydrauilc tank and carefully purging, it sure feels like the 55 gal drum is darned near empty where it should have 13 ish gallons remaining. does 'hydrauilc fluid capacity' just refer to the tank volume? If so, I'd have to guess where 12-13 gallons went. Maybe a gallon for the filter, 3 for each steering ram, main suction line 2, feed lines, 1 each. perhaps that comes up to nearly 10 plus other dribbles. I guess that's the question, is capacity different than total volume.
Some manuals are not very clear. The only way to be certain is if the manual has 2 numbers in it, one for the tank capacity and the other for total system capacity - a lot of Cat manuals are written that way. Also you should bear in mind that anything in the manuals is at best approximate. I don't know if you've seen this but I take "hydraulic sump" (RH side of page 2) to mean the tank and 120 quarts is 30 gallons - so maybe the 55-gllon drum isn't lying .......... https://www.deere.com/en_US/docs/construction/non_current_products/wheel_loaders/644EH.pdf
Nige, thanks, I did see that where in that one spot it called out 'tank' perhaps order up a few pails of mobilfluid 424 to to the transmission service, keep some on hand and get a few buckets of mobilfluid LT for the Kubota. then get my $10 deposit back on the 55 gal drum. I suppose 15 gallons less of old fluid is a good thing! as the point is cleaning the system out.