content_image/577946.jpg
<img src='content_image/577946.jpg'>

3. Check the swivel nut for tightness. 

4. If the servicing valve is equipped with a valve core, depress it to release any air pressure that may be trapped under the core in the valve body. [Figure 13-25B] Always be positioned to the side of the trajectory of any valve core in case it releases. Propelled by strut air pressure, serious injury could result. 

5. Loosen the swivel nut. For a valve with a valve core (AN2687-1), rotate the swivel nut one turn (counter clockwise). Using a tool designed for the purpose, depress the valve core to release all of the air in the strut. For a valve without a valve core (MS28889), rotate the swivel nut sufficiently to allow the air to escape. 

6. When all air has escaped from the strut, it should be compressed completely. Aircraft on jacks may need to have the lower strut jacked with an exerciser jack to achieve full compression of the strut. [Figure 13-26] 

7. Remove the valve core of an AN6287 valve [Figure 13-25D]  using a valve core removal tool. [Figure 13-27]  Then, remove the entire service valve by unscrewing the valve body from the strut. [Figure 13-25E] 

8. Fill the strut with hydraulic fluid to the level of the service valve port with the approved hydraulic fluid. 

9. Re-install the air service valve assembly using a new O-ring packing. Torque according to applicable manufacturer’s specifications. If an AN2687-1 valve, install a new valve core. 

10. Inflate the strut. A threaded fitting from a controlled source of high pressure air or nitrogen should be screwed onto the servicing valve. Control the flow with the service valve swivel nut. The correct amount of inflation is measured in psi on some struts. Other manufacturers specify struts to be inflated until extension of the lower strut is a certain measurement. Follow manufacturer’s instructions. Shock struts should always be inflated slowly to avoid excess heating and over inflation. 

11. Once inflated, tighten the swivel nut and torque as specified. 

12. Remove the fill hose fitting and finger tighten the valve cap of the valve. 

## Bleeding Shock Struts 

It may be necessary to bleed a shock strut during the service operation or when air becomes trapped in the hydraulic fluid inside the strut. This can be caused by low hydraulic fluid quantity in the strut. Bleeding is normally done with the aircraft on jacks to facilitate repeated extension and 

