Mitey mac 8A hydraulic drain question

[Labradigger1]

Hello all, first post here. Short story, bought the above mentioned skid steer and want to change hydro fluid. For the life of me I don't see a drain plug on the hydro resivoir tank. It is kind of dark where I'm working on it so I may be overlooking it. Bought it is needing a new engine and once home a set of points, condenser, plugs, oil and filter change, carb clean and fuel change took care of the engine. Left hydrostatic drive was not working, dissambled pump and lapped all parts. Nothing major I see wrong in the pump/motor except the 6210 2rs bearing inside the lower v pulley is toasted. Currently waiting on new seals to come snail mail for the 15 series pump/motor so figured I would change out fluids. Hydro fluid is severely water saturated and my plan is to changed it twice with a filter after reaching operating temps. Looks like pdf manuals I found for the gene 2500 shows atf type f or dextron for hydro fluid. When I removed the old hydro filter I was amazed at the amount of fiber like filth that was plugging the old filter, I'm guessing it was a rope/oakum type packing that broke loose from ram packing. Thanks for any assistance or "be sure to check out" items.

 

[walio123]

Is the hydraulic oil not leaking after one pump / motor has been dismantled? If the hose is plugged in, remove the plug and drain from there. Once there is plenty of water in the system, I recommend washing it before you fill it with oil. With a pretty interesting machine you got yourself. Good luck

 

[Labradigger1]

Is the hydraulic oil not leaking after one pump / motor has been dismantled? If the hose is plugged in, remove the plug and drain from there. Once there is plenty of water in the system, I recommend washing it before you fill it with oil. With a pretty interesting machine you got yourself. Good luck

Only one pressure hose has been disconnected. The supply line to the left hydrostatic drive. I lost very little fluid from the hose, maybe around 1/3rd cup. It has not been leaking since and I'm afraid to start the engine to pump it out because it may cause damage from being starved of lubrication. I rigged an electric fluid pump up yesterday and pumped all but about 1/2" from the resivoir and what remains in other hoses, rams and pumps. As of now I filled it with fluid and one I prime and install the rebuilt drive I'll let it warm up and pump it out and change the filter again. It would be nice if it had a drain plug at the bottom of the resivoir since oil floats on water but darned if I see one anywhere. It would also be nice if I had a better understanding of hydraulics in general but I'm doing ok. I do have good mechanical ability and fair fabrication skills and also a good metal lathe so that all helps. Looks like some parts will arrive beginning tomorrow for the Sundstrand 15 u series drive. I've done about all I can except locating leaks in the tires until the drive is reinstalled. Thank you for the reply.

 

[walio123]

Only one pressure hose has been disconnected. The supply line to the left hydrostatic drive. I lost very little fluid from the hose, maybe around 1/3rd cup. It has not been leaking since and I'm afraid to start the engine to pump it out because it may cause damage from being starved of lubrication. I rigged an electric fluid pump up yesterday and pumped all but about 1/2" from the resivoir and what remains in other hoses, rams and pumps. As of now I filled it with fluid and one I prime and install the rebuilt drive I'll let it warm up and pump it out and change the filter again. It would be nice if it had a drain plug at the bottom of the resivoir since oil floats on water but darned if I see one anywhere. It would also be nice if I had a better understanding of hydraulics in general but I'm doing ok. I do have good mechanical ability and fair fabrication skills and also a good metal lathe so that all helps. Looks like some parts will arrive beginning tomorrow for the Sundstrand 15 u series drive. I've done about all I can except locating leaks in the tires until the drive is reinstalled. Thank you for the reply.

Simply disconnect the charging hoses from the gear pump and hydrostatic pumps / motors. Put appropriate containers to collect the oil. The water is heavier than the oil and sinks at the lowest points. In no case does the engine start. You can also unhook the hoses of the hydraulic cylinders, and if you have a suitable winch lift you can raise the boom and then let it go slowly. The same should be done with the bucket cylinders. If you do not have a winch, you can dismount the hydraulic cylinders and stretch and push the rods all the way. So almost no water will remain.