The connections may only need tightening to eliminate POWER STEERING leaks; however, leakage may occur at various points in the  power  steering  unit  if  the  seals  are  defective. Power   steering   (fig.   3-2)   adds   the   following Document conditions and report them to the mainte- components to the steering assembly: a hydraulic pump, nance shop for replacement of any defective seal. a fluid reservoir, hoses, lines, and a steering assist unit whether mounted on the linkage or incorporated in the The  types  of  steering  troubles  that  develop  in steering  gear  assembly. vehicle  operations  that  should  be  documented  and turned in for repair are as follows: ARTICULATED STEERING l l l l l l l Excessive play in the steering system Hard  steering Vehicle   wanders Vehicle pulls to one side when braking Front-wheel  shimmy Front-wheel tramps (high-speed shimmy) Steering  kickback Tires  squeal  on  turns Improper  tire  wear Unusual   noises Hydraulic power is used to turn a whole section of a machine on a vertical hinge. This design is called articulated  steering  and  it  is  controlled  by  a  steering wheel,   a   hydraulic   control   valve,   and   hydraulic cylinders. (See fig. 3-3.) The pivot is midway in the vehicle, so both parts share equally in the pivoting. This action produces the effect of four-wheel coordinated steering,  such  as  the  front-and-rear  wheels  run  in  each others  tracks,  backward  and  forward. FRONT-AND-REAR  STEERING Wheeled equipment may be designed to steer by angling the front wheels, the rear wheels, and or both These  problems  must  be  documented  and  turned  in the  front-and-rear  wheels  (fig.  3-4).  Front-wheel for   repairs. steering is the standard method. The vehicle follows the Figure 3-2.-Power steering linkage assembly. 3-2