Visually inspect the power assisted steering fluid level in the reservoir

Carry out a test by steering on full lock and then releasing the steering wheel

Move onto step 1

• Restore the correct level. if there are leaks,

Move onto step (see X30)

Move onto step 2

• No intervention of any sort is needed: the noise is due to the by-pass valve discharing excess pressure

End of diagnosis

Move onto step 4

Check:

• reservoir breather plug
• reservoir filter

Move onto step 2

• Clean or replace the plug

End of diagnosis

• Replace the reservoir Op. 4130B10

End of diagnosis

Visually inspect the power assisted steering fluid in the reservoir.

Make sure that there is no emulsified oil (oil which is lighter in colour and with bubbles)

Move onto step 3

• Eliminate any air penetration through the power assisted steering system pipes (see Assembly 4310B)

End of diagnosis

Check whether there are any restrictions in the system pipes, flexible and rigid

Move onto step 4

• Replace the damaged parts, replacing all the seals (see Assembly 4310B)

End of diagnosis

Carry out a test rotating the steering wheel slightly firstly with the engine running and then with it switched off: check that the knocking takes place both with the engine running and with it switched off

Move onto step 5

• Replace the power assisted steering pump Op. 4130B20

End of diagnosis

Check the condition of the steering tie-rods and arms.

Move onto step 6

• Replace the tie-rids or balljoints Op. 4110B14

End of diagnosis

• Replace the steering box Op. 4130A10

End of diagnosis

Check that there is not too much play in the steering column; check the condition and the efficiency of the steering column support bearings

Move onto step 7

• Replace the bearings involved Op. 4110A30

End of diagnosis

Check that the fault is no longer present

End of diagnosis

Incorrect selection of diagnostic procedure