The steps for installing the piston Y-shaped oil seal are as follows:

1. Clean the piston rod and sealing groove: First, use a clean cloth or tissue to wipe the surface of the piston rod to ensure it is clean and free of oil stains. Then, use a scraper or brush to clean the sealing groove, ensuring that there are no debris or dirt inside.

2. Apply lubricant: Apply a certain amount of lubricant on the surface of the piston rod. The selection of lubricants should be based on the actual situation, and can be consulted with professionals or refer to the equipment manual.

3. Install piston oil seal: Place the Y-shaped oil seal coated with lubricant in the sealing groove, ensuring that it fits tightly with the piston rod. Gently press the oil seal with your fingers or tools to ensure it is fully inserted into the sealing groove.

4. Check installation quality: After installation, carefully inspect the installation quality of the piston oil seal. Firstly, check if there is any gap or gap between the oil seal and the piston rod. If there is, it needs to be reinstalled. Secondly, check whether the oil seal is tightly fitted in the sealing groove and whether there is any deformation or damage. Finally, gently pull the piston rod to check if the oil seal can move normally.

Please note that these steps may vary depending on the device model and manufacturer's recommendations. Therefore, before installation, it is best to refer to the equipment's operating manual or consult the manufacturer for accurate installation instructions.