To add hydraulic fluid to a log splitter, drain out the existing fluid from the splitter's reservoir, add the required amount of fresh fluid into it using a funnel, and check the fluid level using a dipstick. Position the splitter above ground level to make the task easy.
Begin adding hydraulic fluid to a log splitter by placing the tool on sawhorses or a few blocks to raise it above ground level. This gives better access to the drain plug of the splitter's reservoir for hydraulic fluid.
Then, position a bucket or some other suitable container beneath the drain plug of the reservoir for the hydraulic fluid, and take out the cap of the reservoir's fill tube. Now, remove the drain plug by unscrewing it or pulling it out, and allow the existing hydraulic fluid to collect in the bucket. After draining out the entire fluid from the reservoir, reposition the drain plug.
Next, position a funnel in the reservoir's fill tube, and add 1 1/2 gallons of suitable hydraulic fluid into the reservoir through it. Finally, take the funnel out, and insert the dipstick present on the cap of the fill tube to check if the fluid level in the reservoir is adequate.