Would like to drain the hydraulic tank to replace a piece of hose in the pump inlet line while saving the fluid. Have found only a small plug on the right side in a not to easy place to get a bucket under. Is opening a line into a bucket a possibility? '67 D4/D4D 78A7171.
What's the s/n of the hydraulic system? Should be a tag with number on the tank.
It will take a few days before I can look for the number OM.
One option. Don't drain it. if there is a breather on the tank remove it and connect a vacuum hose to that port. Does not have to be a super strong attachment, maybe a pipe nipple with a bit of duct tape to hold the hose on and somewhat sealed. I have a little homemade device that uses shop air pressure to create vacuum by venturie action. It has been good enough to allow me to remove a hydraulic pump mounted under the tank on a loader with something like 2 inch intake off the bottom of a tank holding 30+ gallons of oil. Trick doing that is to loosen the suction line and slip a thin metal plate in the gap while the suction device is working. Just don't let someone turn off air compressor or unhook the hose! Another option if out in the field working hooking a hose from a vacuum fitting on you gas engine-ed truck to the breather port on the tank. Don't think this would work with a diesel as far as I know they don't pull a vacuum in the intake, or not enough to do the job. Suppose in a pinch you could restrict the intake enough to it pull a vacuum, wrap the air filter with some duct tape?? One more thing. If the oil level in tank is too close to the breather port you could actually suck some oil out doing this, BTDT! I'll try to draw up a sketch of this little tool someday soon. Very simple to make just need to drill some holes the right size and in relation to each others and tap a couple holes for pipe threads.
One might run a line off a test port into a bucket. Then at a idel run till u hear the pump skip them shut off. Most of the oil will be out. Drain what's left out the plug and u don't have to worry about dirt in most of your oil. Some might frown on such a practice. I do that with transmission oil to if it has to b reused. DARO
I'm going to guess it's a 62Gxxxx series #141 Hydraulic System. Take a look at the pump suction line between the pump and the hose coupling. There is a pipe bung and plug on this section of the line that would drain the tank and suction line or at least most of it down to the tank line connection. The rest you'd have to suction gun out the side plug access on the tank itself.
I've used that same kind of method on the old Bobcat where I worked. For some reason the factory did not see fit to install any drain. Service manual says pull off suction hose to drain oil. How the heck you suppose to catch it! Just take off one of the tilt cylinder hoses and start engine. Work control to put oil out the hose and into a can. Kill engine as soon as the pump growls from air.
That's the quickest method when the drain plug is unhandy to get to . Suction from a shop vac on top of the tank will also work when swapping out a line or hose when you don't want to drain the tank down.
If I'm draining the tank most of the time I use my barrel pump that I pump diesel with. Hydraulic oil will pump almost as fast as diesel. It also keeps the oil clean and I can pump it back in when I'm ready.