The frustration of the difficulty in removing the damaged YAW PISTON from a GE wind turbine an be easily resolved by use of the WECS design Yaw Puller device shown here.
Basic Instructions for the use of the WECS WGEYPP:
WECS introduces a new tool developed to remove seized GE Yaw Brake Pistons. The WGEYPP is designed to be portable and extract the most severely seized pistons with the use of a hollow bore hydraulic cylinder with up to 30 tons of force. The four special tools below along with the high strength threaded rod and connecting nuts, are provided in a Pelican protective case.
1. Remove all hardware surrounding the piston to be extracted. (Locknut, Adjusting Bolt, Snap Ring, Closing Nut, Spring Carrier, all springs and spring retaining O-ring, Shim Ring)
2. Place Tap on top of the piston.
3. Install Tap Guide by threading into thread used for the Closing Nut. Thread down as far as possible without contacting the back of the Tap.
4. Using a wrench start the tapping process using standard alternating Clockwise and Counter Clockwise motions. Continue the tapping process until the tap bottoms out.
5. Remove the Tap Guide and unscrew the Tap and remove.
6. Inspect and clean new threads.
7. Thread Pulling Plug into the piston using the newly cut threads.
8. Install threaded rod into the center of the Pulling Plug
9. Place Cylinder over the threaded rod. If clearance is tight placing the rod in the cylinder before threading into the Pulling Plug may be warranted.
10. Install washer and locking nut on the threaded rod, and thread down to top of cylinder.
11. Activate the cylinder to extract piston.
12. If piston does not release, retract cylinder, reset locking nut and activate cylinder. If additional travel is required to remove piston, extend locking nut on the top of cylinder by 2” and place the Spacer between the hydraulic cylinder and the piston sleeve. ( Note: the spacer has a raised boss on the bottom so it will self center in the piston sleeve. Also the spacer is slotted so that the threaded rod does not need to be remover to add the spacer)
13. Once piston is removed clean the piston sleeve as required and reassemble per turbine manufacturer’s instructions.