YQK Hydraulic Cutter: Common Faults & Troubleshooting Guide

Common Faults & Solutions
Q: The hydraulic cutter cannot build pressure. How to fix it?
A: Identify the specific symptom:
A. No response when pressing the handle.
Cause: Return valve (Point A) fails to close, causing oil to flow back into the reservoir.
Solution:
Pull out the piston, unscrew the check valve, and remove the steel ball.
Blow compressed air through the valve, then reassemble.
If check valves (Points B/C) are stuck, gently tap the cutter head to reset the balls.
B. Piston stops advancing after mold contact.
Cause: Check valves (Points B/C) fail to close fully.
Solution: Repeat the valve resetting steps in A3.
C. Piston retracts slowly when pressure stops.
Cause: Debris on the return valve’s steel ball creates a micro-leak.
Solution:
Loosen the return valve, pump the handle repeatedly, then retighten.
If unresolved, disassemble the valve, clean the ball with compressed air, and reassemble.
D. Piston reciprocates with handle movement.
Cause: Points A/B are jammed, forcing oil to cycle between AC/BC chambers.

External Leaks (Seal Wear)
Return Valve Leak
Remove the valve, extract the plunger, and replace the P-type seal (ø8×1.9G83452.1-92).
Pump Core Leak
Detach the handle, pull out the core, replace the seal inside the screw plug.
Piston Leak
Extract the piston, install new seals with lubricant, and reassemble.

Maintenance Guidelines
Storage: Loosen the return valve screw; clean and apply anti-rust grease.
Refilling Oil:
Rotate the fixed handle, unscrew the tail pipe, and pump residual oil into the cylinder.
Refill with hydraulic oil to purge air, then tighten all components.

Prohibited Actions
NEVER pressurize the cutter without installed dies.
NEVER loosen, rotate, or detach the cutter head during operation.
NEVER use extended handles.
NEVER use non-specified fluids.