Engine Driven Pump Declutch
The declutch, which is a part of the engine-driven pump, includes a mechanical device that has an effect on the pump shaft level.
The declutch can be used when a pump malfunction occurs.
The disengagement can be done manually from the ground, when the engine is stopped, use a 3/8 inch square drive tool on the reset port. On the Engine Driven Pump, there is a visual indicator which gives the position of the clutch: reset, engaged or disengaged.
When the EDP is declutched, the re-engagement cannot be done from the cockpit.
After trouble identification and correction, the re-engagement of the pump to the engine accessory gear box is done manually when the engine is stopped: Remove the cover, pull release cable and reinstall cover.
The new engine driven pumps include a disengagement clutch at the drive from the engine. This lets the maintenance personnel de-activate the pump for an approved flight dispatch with an inoperative pump.