Changing splitter hydro oil

[xman23]

I'm considering changing the hydro oil and filter in my MTD splitter. I bought this used 10 years ago and I don't think either have ever been changed. The oil looks good, clear not milky.

My concern is getting air in the system. What's the procedure? How do you keep the air out, or get it out. What oil do you use?

Thanks

 

[triptester]

Air is normally self purging in a log splitter. After changing fluid with the engine at half throttle extend and retract the cylinder fully several times to purge the air. Recheck the fluid level after purging the air and cycle the cylinder a couple more times. This will usually purge all the air from the system.

 

[TreePointer]

Air can also mix into the fluid if there isn't sufficient fluid present in the system, so keep your reservoir in the safe operation zone.

The splitter manuals I've seen these days recommend SAE20 or ISO46 hydraulic fluid for general use and possibly ATF if operating mostly in cold weather.