11. FAULTS AND REMEDIES
The ZF Single Circuit Power Steering Gear has been developed for high demands. The system has
been designed in such a manner that no faults will occur with satisfactory maintenance during
normal operation. If unexpected trouble should nevertheless show up at one time or other, the
following information should be of assistance for pertinent location and removal.
Prior to checking the steering system for individual troubles, check the oil level with the engine
running, a gear step engaged and with the driving axle for the drive dependent pump jacked up.
The accurate procedure of filling-in the oil is described in detail in Section 4, page H-16.
Simultaneously we added that the use of heavily foaming oils may lead to trouble, since such oils
will release any air, after entering the steering system, with difficulty only or not at all.
For finding the cause of a fault, each steering circuit must be tested
and checked separately: On three-pump steering systems the two
engine-dependent pumps in steering circuit I and II on stationary
vehicle with engine running. The drive-dependent pump (emergency
steering pump) in steering circuit I on rolling vehicle (drive axle for
drive-dependent pump driven on roller-type dynamometer) with