Wood splitter is pushing hydrolic fluid out fill tube on the return stroke

There is usually a hydraulic pump on those units. Check and see if it is low on oil. Check and see if there is a shear pin that has broken on the shaft that goes to the pump.

Dear Kathleen,
The problem should be back pressure.
The reservoir should have no pressure in it at all, but a blocked return line, a crimped hose or tube, or a internally leaking pump can cause these problems.
Something is causing the pump pressure to enter the reservoir.
It might be time to have someone look at it.
God bless your efforts.

Hi Grover:
If this is your transmission, you fill it through the tube that the dip stick lives in.
Same for power steering, only power steering unit, not transmission..

Make sure you hydrolic fluid tank has the proper amount of fluid.

Replace the Hydraulic oil in the log splitter after
every 150 hours of use. Take following steps to
replace it.

1. Make sure all moving parts stops and the log splitter is unplugged.
2. Unscrew Oil Drain Bolt with Dipstick to remove it.
3. Turn the log splitter on the Support Leg side over an 4 liters capacity container to drain the hydraulic oil off.
4. Turn the log splitter on the the motor side.
5. Refill fresh hydraulic oil at the volume as per the hydraulic oil capacity of a particular model indicated in above specifications table.
6. Clean the surface of Dipstick on the Oil Drain Bolt and put it back into the oil tank while keep the log splitter vertically.
7. Make sure the level of the refilled oil is just between 2 grooves around the Dipstick.
8. Clean the Oil Drain Bolt before thread them back. Make sure they are tightened to avoid leakage before place the log splitter horizontally.

Periodically check oil level to ensure it is between
2 grooves around the Dipstick. Upon Lower oil
level, oil refilling is required.

Source:
http://www.qci.net/files/5_Ton_Log_Splitter_-_USE_THIS_MANUAL.pdf

the piston contains your hydraulic fluid. By following any hose coming out of the piston you should be able to chase down the reservoir.

keep you fluid level above 3/4 full- assuming you have a hydrolic clutch- unhook negitve battery cable remove rubber cap from bleeder screw on the release cylinder.place place a bleeder tube over the end of the bleeder screw.sumerge other end in a jar thats half full of hydrolic brake fluid.slowly pump the clutch pedal fully and let return slowly several times requires two people while pressing clutch to the floor lossen bleeder untill fluid comes out then close keep repeating this while keeping an eye on your bleeder tube jar as soon as you see no more bubbles close the bleeder screw and again make sure to keep an eye on resivor to remain 3/4 full or will get air in the line and have to start over. this part should be located on the tranny this is for hydrolic bleeding system refure to your owners manual for your type and location of your clutchrelease slave cylander.

We have one of these splitters and the only problem has been a control valve sticking down. Oiled the valve button with silicon oil which seems to have helped. Be sure to close the bleeder valve when putting the machine away. We bought the machine from Home Depot. Use some headphones for your music! We have split rounds much larger than recommended by splitting from different sides. Hope this helps!

Hydraulic lift seal needs to be replaced so that the fluid
will not be pushed out. Okey, God bless you.

What's going on is the seals are worn out on the inside and the fluid is bypassing. This is why it is slow.....while operating it, feel it. If it is hot, it's bypassing....the actuator (cylider that houses the piston) needs rebuilt.

If you can get the specs on this, it is really easy to reseal....pressure testing is another thing....take it to a rebuild shop. get this done and it will last another 30 winters!

Good luck!