|  |  | 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 
                               1 | 
| The noise remains constant (hissing during steering,
puffing on release) | No intervention of any sort is needed: the noise is due
to the by-pass valve discharing excess pressure | 
| 1 | 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 
                              2 | Emulsified fluid | Eliminate any air penetration
through the power assisted steering system pipes (see Assembly 4130B) | 
| 2 | 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 
                              3 | Pipes faulty | Replace the damaged parts,
replacing all the seals (see Assembly 4130B) | 
| 3 | POWER ASSISTED STEERING PUMP CHECK | All OK | Problems met | Operation | 
|---|
|  | Check
that the power assisted steering pump is working properly | Continue to Step 
                              4 | Power assisted steering
pump malfunction | Replace the power assisted steering pump 
                               Op.   4130B20 | 
| 4 | 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' |