Bleeding a Shock Strut

Bleeding a Shock Strut

If the fluid level of a shock strut has becomeextremely low, or if for any other reason air is
trapped in the strut cylinder, it may be necessary to bleed the strut during the servicing operation. Bleeding is usually performed with the aircraft placed on jacks. In this position the shock struts can be extended and compressed during the filling operation, thus expelling all the entrapped air. The following is a typical bleeding procedure :
 Construct a bleed hose containing a fitting suitable for making an airtight connection to the shock strut filler opening. The base should be long enough to reach from the when the aircraft is on jacks.

Jack the aircraft until all shock struts are fully extended.


Release the air pressure in the strut to bebled.

Remove the air valve assembly.

Fill the strut to the level of the filler port with an approved type hydraulic fluid.
Attach the bleed hose to the filler port and insert the free end of the hose into a container of clean hydraulic fluid, making sure that this end of the hose is below the surface of the hydraulic fluid.

Place an exerciser jack  or other suitable single-base jack under the shock strut jacking point. Compress and
extend the strut fully by raising and lowering the jack until the flow of air bubbles from the strut has completely stopped.

Compress the strut slowly and allow it to extend by its own weight.

Remove the exerciser jack, and then lower and remove all other jacks.

Remove the bleed hose from the shock strut.
Install the air valve and inflate the strut