look in how to bleed air off cooling system
Remove cap from PS pump and turn wheels "lock-to-lock" several times. This procedure should bleed air from PS lines.
You have a bleed screew in the top hose from the radiator undo it slightly to let the air out.Once bleed retighten the screw.
Use the bleeder valve to bleed the system.
Loosen cap on reservoir turn wheel lock-to-lock several times without holding in lock position.
normally you keep turning the steering to full lock both sides and the pump should bleed itself.
Self bleading ,turn stearring fom lock to lock with engine runing
It should bleed its self when turning lock to lock while engine is running.
I suspect an air lock in the coolong system. The bleed screw is located on the pipe running just above the gearbox, It's an 8mm socket that fits the bleed screw.
You may have an air lock in the heater pipes some vehicles are fitted with bleed screws for this purpose.
You don't bleed power steering fluid. Raise the front of the car, start the engine, turn the steering wheel lock-to-lock 3 times to get the air out of the system. Make sure to use axle stands and block the wheels so you can do this safely.
To remove an air lock from a diesel Peugeot, first ensure that the fuel system is primed. You can do this by turning the ignition on (without starting the engine) for a few seconds to activate the fuel pump, repeating this several times. If the air lock persists, locate the bleed screw on the fuel filter or injection pump, loosen it slightly, and manually pump the primer bulb until fuel flows out without air bubbles. Finally, tighten the bleed screw and attempt to start the engine.