SERVICE MANUAL c. Tighten  all  pump  mounting  bolts  to  speci- fied torque. d. Check belt tension. 2. When the power steering pump is driven by two belts in a matched set: a. Follow  same  checking  and  adjusting  pro- cedure as 1  above,  but  if  it  is  necessary  to  replace  one belt,  both  must  be  replaced  by  a  new  matched  set  to equalize belt tension in both belts.  Check tension in both belts. 3. When  the  power  steering  pump  pulley  is  driven by one primary belt and is used as an idler for a second belt driving some other accessory: a. Follow  same  checking  and  adjusting  pro- cedure for the primary power steering pump drive belt as for above. b. Recheck and adjust as necessary the pump belt  tension  after  adjusting  tension  on  belt  driving  the other accessory. DIAGNOSTIC INFORMATION GENERAL INFORMATION Complaints of faulty steering are frequently the result of  problems  other  than  the  pump.  Those  areas  of  the steering system which can be easily checked and quickly corrected without disassembly and overhaul of any major components should be attempted first. Conditions   such   as   hard   or   loose   steering,   road shock  or  vibrations  are  not  always  due  to  the  steering gear   or   pump,   but   are   often   related   instead   to   such factors   as   low   tire   pressure   and   front   end   alignment. These  factors  should  be  checked  and  corrected  before any   adjustment   or   disassembly   of   the   power   steering pump is attempted. Many  factors  affect  proper  operation  of  the  steering system, of which the most common are: 1. Fluid level and condition. 2. Drive belt tension. 3. Loose component mountings. 4. Loose pump pulley nut. These  factors  must  be  checked  and  corrected  be- fore making any further diagnosis of the steering system. The need for proper diagnosis cannot be overemphasized. After   the   source   of   the   problem   has   been   found, determine the cause.  For example, if the oil level in the reservoir  is  found  to  be  low,  refill  and  check  the  entire hydraulic system for oil leaks.  Refilling the reservoir will not necessarily correct the problem. When   reference   is   made   to   power   steering   gear components  in  the  following  charts,  it  will  be  necessary to  determine  which  gear  the  vehicle  is  equipped  with, and  then  refer  to  the  appropriate  manual  in  your  CTS- 4001   Truck   Service   Manual   for   gear   adjustment   and repair procedures. DIAGNOSTIC CHARTS CONDITION POSSIBLE CAUSE CORRECTION Chirp noise in steering pump 1 Loose belt 1 Adjust belt tension to specifica- tion. Belt squeal (particularly no- 1 Loose belt 1 Adjust belt tension to specifica- ticeable during steering at tion. full wheel travel and stand- still parking) Growl noise in steering pump 1 Excessive back-pressure in 1 Locate restriction and correct. hoses or steering gear Replace part if necessary. caused by restriction Growl noise in steering pump 1 Scored pressure plates or 1 Replace parts and flush system. (particularly noticeable at carrier standstill parking) 2 Extreme wear of cam ring 2 Replace parts. and rolls CTS-4027 - Page 4 SERVICE MANUAL