The auxilary water pump is fitted to 21 turbos, 19 16V's and Clio 16V's. It purpose is to pump coolant around after engine shutdown to prevent localised boiling of the coolant.
It does this by a relatively small amount, it takes coolant from the top radiator hose and pumps it into the lower radiator hose.
Its a centrifugal pump, similar to a turbocharger.
The pump is sealed off from the motor unit, the pumps impellar is actually turned by magnetism. Simple yet effective.
However it fails in a number of ways. The magnet on the impellar attracts all the ferrous metal (rust etc) in the cooling system, this jams it or at least makes it noisy, the pump itself can stick and fail or in 1 case I have seen the magnet on the pump actually breaks up! The impellar runs on bushes which can swell and crack and also att he same time crack the impellar.
With the pump removed, theres 4 phillips screws that hold the houring onto the pump. Chances are these are very corroded, sometimes they will just unscrew. If they don't you can either leave it alone or what I do is get a junior hacksaw and cut along the screw holes, a small slot allows it to open up enough to slide the housing off. The slot int he threaded part will relieve the grip on the screw and you can remove the broken screw with mole grips or similar.
With the pump apart you are left with these parts, the pump (left), impellar and housing and the end cap.
This particular pump came from my old white chamade
This shows the impellar removed from its housing, yes thats rusty scale from the cooling system stuck to the magnet
A lot of water and toothbrush work later it was liek this, good as new!
This is the housing, water from the top hose comes in the centre and it is flung out to the sides of the housing and out the vertical pipe by centrifugal force.
The pump, still had 2 screws left in it to be removed. Slot cut and grips wound them out
Back together with new screws and the pump worked fine, never did actually fit the right plug to the wires on this pump.
Linear Mode
