If you exceed the airspeed limit for the gear and/or flaps, you will experience hydraulic failure. Once this happens, the system is frozen.
Get the speed below 180kts, and toggle the hydraulic system switch just behind the thrust lever quadrant to extinguish the amber warning light on the instrument panel. Then select gear/flaps as required, making sure not to exceed 180kts until gear/flaps are raised.
Take care
