© © 2012 Delmar, Cengage Learning Steering System Service Chapter 66

© © 2012 Delmar, Cengage Learning Objectives Describe problems with steering system components Inspect the condition of the steering system Explain different types of repairs that can be made to the steering system Describe repair procedures for rack-and-pinion and parallelogram steering systems Perform steering system repairs in a safe and professional manner

© © 2012 Delmar, Cengage Learning Introduction Normal use –Steering parts remain separated by lubricants Seals are damaged and lubricants leak –Parts rub against each other Road hazards –Cause hard impacts to steering parts Belts and hoses can fail –Results in operational problems

© © 2012 Delmar, Cengage Learning Fluid Level Checks Power steering fluid level –Should be checked hot –With engine idling: turn wheel several times in each direction –Before shutting off engine: check fluid level

© © 2012 Delmar, Cengage Learning Type of Fluid Power steering fluid is recommended in power steering systems –Use manufacturer's recommended fluid

© © 2012 Delmar, Cengage Learning Diagnosing Steering Problems and Noise Diagnosis Causes of steering and suspension problems –Play and looseness –Incorrect height –Wheels not aligned to specifications Causes of noise from steering system –Loose power steering belt –Pump bypassing pressure –Lack of fluid in power steering reservoir

© © 2012 Delmar, Cengage Learning Hard Steering and Tire Wear Causes of hard steering –Lack of steering fluid –Binding in the steering linkage –Steering gearbox problems –Low tires –Incorrect wheel alignment settings Steering and suspension problems –Often result in unusual tire wear Worn parts cause scalloped or gouged tire wear Improper alignment adjustments cause tire wear

© © 2012 Delmar, Cengage Learning Steering Part Inspection and Steering Linkage Inspection Inspect steering system before wheel alignment –Inspect wheel bearings Wheel bearing is loose: wheel alignment equipment cannot make accurate readings Steering linkage inspection –Best way to discover looseness is dry park check –Look for loose parts while observing the steering and suspension as wheels turn –Steering linkage cab be inspected while vehicle is in air during lube inspection

© © 2012 Delmar, Cengage Learning Steering Gear Looseness Causes of excessive steering wheel free play –Worn steering linkage –Worn flexible coupling at steering column –Worn or misadjusted steering gear Steering wheel free play –Check with the engine off

© © 2012 Delmar, Cengage Learning Parallelogram Inspection Important points –Check sockets for looseness or damage to seal –Idler arm movement can cause tire wear –Small amount of movement where pitman arm attaches to steering linkage is often normal –Inspect tie-rods for wear

© © 2012 Delmar, Cengage Learning Rack-and-Pinion Steering Linkage Inspection Important points –Feel for looseness by grasping the tie-rod through bellows boot –Should not be any looseness between inner tie- rod ball and socket If tie-rod is hanging down in its socket: it could be bound up

© © 2012 Delmar, Cengage Learning Steering Linkage Repairs and Idler Arm Replacement Steering linkage parts are locked together by wedging them against each other with “tapers” –When disassembling tapers to service or replace parts, there are several ways to get them apart Idler arm replacement –Check to see if it one of the adjustable types –Bump steer causes toe to change when going over bumps Causes tire wear

© © 2012 Delmar, Cengage Learning Pitman Arm Replacement Important points –Removal requires a special puller –Must be replaced in the same position on the splines of the steering gear –Check its position before removing it –Pitman arms often have a “blind side”

© © 2012 Delmar, Cengage Learning Tie-Rod End Replacement Characteristics and key points –Tie-rod ends are threaded to provide a means of adjusting toe –Measure old tie-rod assembly before disassembling –Removing old tie-rod end: count the number of turns to remove it –Before tightening tie-rod clamps: check condition and position

© © 2012 Delmar, Cengage Learning Rack-and-Pinion Tie-Rods Inner tie-rod socket is held to ends of steering rack –Several ways Jam nut Special washer staked into flat area at end of rack Roll pin is used to hold tie-rod to rack

© © 2012 Delmar, Cengage Learning Steering Wheel, Column, and Air Bag Service Removal of the steering wheel –Sometimes necessary Air bag service –Driver's side air bag has a clock spring or spiral cable Clock spring must be wound correctly and must be “timed” to steering column Clock spring has a certain amount of travel

© © 2012 Delmar, Cengage Learning Steering Wheel Service Considerations –Do not hammer on end of steering shaft when removing steering wheel –Make alignment marks with centerpunch and hammer

© © 2012 Delmar, Cengage Learning Steering Column Service Can be complicated –Proper service manual should be consulted Causes of noises in steering column –Loss or damaged steering coupling –Misalignment –Bearing or horn ring that lacks lubricant Worn flex coupling –Causes looseness in the steering wheel

© © 2012 Delmar, Cengage Learning Steering Gear Service Most common service is repair of fluid leaks –Damage can be caused by collisions or potholes Steering gears –Occasionally rebuilt by technicians Recirculating ball and nut manual steering gears –Two adjustments to make Preload adjustment High point

© © 2012 Delmar, Cengage Learning Manual Rack Service and Rack- and-Pinion Looseness Manual rack service –Steering wheel on rack-and-pinion must be centered Center of rack is hardened Tie-rods are of different lengths: car steers to one side farther than the other Rack- and-pinion looseness –Steering damper holds tension against rack –Rack gear preload adjustment can be made Rack is worn: tightening this adjustment can result in binding steering at outsides during turns

© © 2012 Delmar, Cengage Learning Power Steering System Service Includes: –Repair and replacement of pump –Hydraulic system flushing –Seal replacement –Belt and hose service –Service and repairs to steering gear –Reservoir service

© © 2012 Delmar, Cengage Learning Power Steering System Flushing Important points –Check condition of hoses –Service life of rack-and-pinion: lengthened by changing steering fluid –Commercial fluid exchange units are available –Fluid can be exchanged without disconnecting hoses –Shop does not have steering flusher: technician flushes steering system manually

© © 2012 Delmar, Cengage Learning Bleeding the System of Air Air in steering system causes erratic operation and/or a growling sound Remove air from system –Be sure tires are lifted off ground –Fluid is warm: run engine at idle and cycle steering wheel from lock to lock several times –Inspect for bubbles –Some technicians bleed power steering air with the engine off

© © 2012 Delmar, Cengage Learning Power Steering Pump Replacement Major steps –Prior to removing Disconnect return hose to drain fluid –Loosen and remove the belt Easier if vehicle is on a lift –Bracket must be removed from pump Note bracket locations

© © 2012 Delmar, Cengage Learning Repairing Power Steering Pump Oil Leaks Integral reservoir –Sealed to pump with a large O-ring –Seals are also located at the pump shaft and fittings for hoses Replacement of pump shaft seal –Requires removal of pulley Front seal leaks and there is sufficient space –Pulley can be removed without removing pump

© © 2012 Delmar, Cengage Learning Power Steering Pressure Diagnosis When pressure is low: there is noise and it is harder to steer the vehicle –Pressure varies: steering effort will be erratic –Check belt tension first –Pressure testing varies among manufacturers

© © 2012 Delmar, Cengage Learning Power Steering Pump Service Defective power steering pumps –Typically replaced with rebuilt pump Flow control valve service –Flow control valve and piston and spring will fall out after fitting is removed –Disassemble and inspect all parts –When relief valve is mounted on outside of pump housing: use a new O-ring during reinstallation

© © 2012 Delmar, Cengage Learning Power Steering Hoses Considerations –System has two hoses Pressure hose Return hose –Sometimes pressure hose has two different ends –Look for signs of leakage or dampness at connections

© © 2012 Delmar, Cengage Learning Refilling the Power Steering System Major steps and considerations –Use correct fluid –After refilling the system: run the engine and check for leaks –Hoses that use O-rings: install new O-rings –Bleed system of air

© © 2012 Delmar, Cengage Learning Power Steering Gear Service Power steering failures –Lack of power assist in one direction –Leakage from steering gear Most shops buy rebuilt power steering gears Rack-and-pinion steering –More prone to problems Weight has been cut –Rack damage Can be due to torsion bar bent from a hard impact or serious leaks

© © 2012 Delmar, Cengage Learning Replacing Rack-and-Pinion Units Major steps and considerations –Sometimes grooves wear in control valve housing –Rebuilt units usually have a nickel-plated sleeve –Remove steering shaft coupler first –Remove roll pins with a punch and chisel –There are usually four tubing connections into top of rack and pinion unit Special crowfoot flare socket might be helpful with removal

© © 2012 Delmar, Cengage Learning Variable Power Steering Service Problems can be mechanical or electrical –Mechanical problem: there will almost always be noise or loss of power assist –Electrical failure: power steering system goes back to operating on full-time power assist Refer to electrical troubleshooting procedure

© © 2012 Delmar, Cengage Learning Electronically Controlled Power Steering System Service Typical complaint: steering too easy or too hard –Perform a visual inspection Correct fluid levels Check belt tension Check electrical connections –Connect a scan tool Electrical defect: diagnostic trouble code will be displayed