The ford cortina uses shocks and springs as its suspension.
The Citroen Xantia uses hydraulics, If you look under the bonnet you
will see a green ball, this is the sphere. The sphere is the unit that
does all of the suspension work.
The main principal of any hydraulic system is, You can compress a gas
but not a liquid.
The Citroen system uses suspension controlled by hydraulics running at
145- to 175- this equates to approx 2750psi.
In the sphere you have a rubber diaphragm, this seperates the hydraulic
fluid from the gas pressure in the top of the sphere, as the wheel
travels up and down the diaphragm in the sphere moves back and forth
giving the comfy suspension found in hydraulic sprung cars.
If you remove the sphere and look into the neck, you will see a silver
looking plate with a small hole in the center, this part is the damper.
The damper controlls the rate or how fast the fluid can get in and out
of the sphere, thus damping the suspension rather than bouncing all
over the place like a tennis ball.
The strut is only a transfer mechanism to transfer the movement of the
rubber diaphragm in the sphere to the wheel. Inside the strut there is
only a piston used to transfer this movement smoothly.
Upon removing the front strut on a Xantia you will find that there is
no resistance at all if you push and pull the piston in and out.
Upon removing the front strut on a ford you will find lots of
Have a look up into the wheel arch of a Xantia, there is no spring,
just a plastic gaiter to stop the muck from getting in.
Try lifting the suspension on a cortina up a few inches to get through
a stream then putting it down again afterwards, all by moving a lever
in the car?
Sorry but ther is no simerlaritys at all. except the fact that both
have round wheels.
Hope this explains something.