|  |  | Results of the tests | 
| 0 | PRELIMINARY CHECKS | All OK | Problems met | Operation | 
|---|
|  | Visually
inspect the power assisted steering fluid level in the reservoirCarry out a test by steering on full lock and then releasing
the steering wheel | Continue to Step 
                              1 | Level too low | Restore the correct level.
if there are leaks, 
                              See table 
                                 X30 | 
| The noise increases towards the end of travel position
and with the engine speed (roaring) | Continue to Step 
                               2 | 
| The noise remains constant | No intervention of any sort is needed: the noise is due
to the by-pass valve discharing excess pressure | 
| The noise is a banging when the steering wheel is in
the centre | Continue to Step 
                               4 | 
| 1 | POWER ASSISTED STEERING FLUID RESERVOIR
CHECK | All
OK | Problems
met | Operation | 
|---|
|  | Verify: reservoir breather plugactual filter
 | Continue to Step 
                              2 | Breather plug blocked | Clean or replace the plug | 
| Filter dirty or blocked | Replace the reservoir 
                               Op.   4130B10 | 
| 2 | POWER ASSISTED STEERING FLUID QUALITY
CHECK | All
OK | Problems
met | Operation | 
|---|
|  | 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) | Continue to Step 
                              3 | Emulsified fluid | Eliminate any air penetration
through the power assisted steering system pipes (see Assembly 4310B) | 
| 3 | POWER ASSISTED STEERING PIPES CHECK | All OK | Problems met | Operation | 
|---|
|  | Check
whether there are any restrictions in the system pipes, flexible
and rigid | Continue to Step 
                              4 | Pipes faulty | Replace the damaged parts,
replacing all the seals (see Assembly 4310B) | 
| 4 | POWER ASSISTED STEERING PUMP CHECK | All OK | Problems met | Operation | 
|---|
|  | 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 | Continue to Step 
                              5 | With the engine running
there is a knocking noise, with the engine switched off it disappears | Replace the power assisted
steering pump 
                               Op.   4130B20 | 
| 5 | STEERING TIE-RODS AND ARMS CHECK | All OK | Problems met | Operation | 
|---|
|  | Check
the condition of the steering tie-rods and arms. | Continue to Step 
                              6 | Rods or arms damaged or
worn | Replace
the steering box 
                               Op.   4130A10 | 
| 6 | STEERING COLUMN BEARINGS CHECK | All OK | Problems met | Operation | 
|---|
|  | Check
that there is not too much play in the steering column; check the
condition and the efficiency of the steering column support bearings | Continue to Step 
                              7 | Bearings worn or damaged | Replace the bearings involved 
                               Op.   4110A30 | 
| 7 | HECK ON CORRECT OPERATION | All OK | Problems met | Operation | 
|---|
|  | Check
that the fault is no longer present | End of diagnosis | Fault persists | Search for the
fault starting from another symptom' |