Subject: | Hydraulic Power Steering System Leak – Required Diagnostic Actions | |
Models: | 2005-2014 GM Cars and Trucks | |
Equipped with Hydraulic Steering |
This bulletin has been revised to add the 2014 model year and to change the tool requiredto remove the steering line fitting seals. Please discard Corporate Bulletin Number07-02-32-002M.
ConditionSome customers may comment on a fluid leak under the front of the vehicle. Upon furtherinvestigation, the technician may find fluid leaking from the power steering system.Please use the following information to assist in diagnosis.
Diagnostic InformationImportant:All potential leaks should be completely cleaned and identified before attemptingto repair or replace any power steering components.
Start diagnosis by inspecting the fluid level in the power steering reservoir. Ifthe fluid level is NOT low, a careful analysis of the condition is necessary as itmay involve a different type of fluid leak.Visually inspect the components where the fluid has accumulated.Before the component is replaced, inspect fittings and connections for proper torque.Clean the area around connections, joints and seals with engine degreaser.Add fluorescent dye (such as Kent Moore GE-28431-6) to the power steering fluid.Start the vehicle and allow the power steering system to reach normal operating temperatures.Turn the steering wheel to the stops in each direction while bumping the steeringwheel against the stops 3-4 times. This will build maximum steering system pressureand help identify the source of the leak if present.Caution:DO NOT hold the steering wheel against the stops as this will damage the power steeringpump.
Determine the source of the leak.When returning the part to the Warranty Parts Center (WPC), mark the component withthe location of the leak using a paint marker, paint or tape to highlight the locationof the leak.If a repeatable leak is found, refer to the following tables to determine the propercorrective action needed.Repairable LeaksPressure feed and return hoses/lines | Replace seals*, hose or line set |
Power steering pump | Reseal or replace pump if necessary |
Cylinder gear/rack lines | Replace O-ring seals or rack lines |
*Steering Line Fitting Seals
Some vehicles are equipped with a “duck-bill“ style seal that is pierced by the powersteering line during installation to the gear at vehicle assembly. Vehicles that areequipped with this type seal are:
2010-2014 Buick LaCrosse2011-2014 Buick Regal2007-2014 Cadillac Escalade2013–2014 Cadillac XTS2005-2014 Chevrolet Malibu2007-2013 Chevrolet Avalanche, Silverado2007-2014 Chevrolet Suburban, Tahoe2007-2013 GMC Sierra2007-2014 GMC Yukon, Yukon XL, Yukon Denali, Yukon Denali XL2006-2010 Pontiac G62007-2009 Saturn AURAImportant:Only insert J-42640 just far enough in to the duck bill seal to get behind the duckbill seal’s steel ring. Then using the tool pry against steel ring to remove the seal.Do not insert the tool too far into the duck bill seal and pry against the housingbore. Prying against the housing bore could scratch the housing bore and require steeringgear replacement.
These seals are replaceable and any leak at the line to gear connection on these vehiclesshould be first addressed with a seal replacement. Use a J-42640 Steering Column Anti-rotationPin (1) to remove the seals (2) and then install the new seals by hand and connectthe power steering inlet and outlet line. This will seat the seals into the steeringgear housing.
Non- Repairable LeaksPorosity leak in the gear/rack housing | Replace steering gear/rack |
Leak from tie rod boots | |
Pinion seal | |
Repeatable leak at steering gear adjuster plug* | See note below |
*If fluid is observed at the adjuster plug during the initial visual inspection, thenrefer to the following:
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Seepage at the adjuster plug may not necessarily indicate an active leak.You can distinguish seepage from an active leak by removing the left tie rod bootclamp and inspecting for the presence of fluid at the inner tie rod.If no fluid is found in the left tie rod boot, replace the boot clamp and clean theseepage (likely manufacturing residue) from the rack. No further action is needed.If fluid is found in the left tie rod boot, replace the gear assembly.Warranty InformationFor vehicles repaired under warranty please refer to the Labor Time Guide and claimthe applicable Labor Operation for the repaired or replaced component. Failure toreturn the replaced part with the location of the leak clearly marked or if thereis no evidence of dye being used to identify the source of the leak may result ina debit of the entire warranty claim.
GM bulletins are intended for use by professional technicians,NOT a "do-it-yourselfer". They are written to inform thesetechnicians of conditions that may occur on some vehicles, or toprovide information that could assist in the proper service of avehicle. Properly trained technicians have the equipment,tools, safety instructions, and know-how to do a job properly andsafely. If a condition is described, DO NOT assume that thebulletin applies to your vehicle, or that your vehicle will havethat condition. See your GM dealer for information on whetheryour vehicle may benefit from the information. | WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION |
Engine Identification
Vehicle Identification NumberThe Vehicle Identification Number (VIN) Derivative is located in two places on theengine and is a nine digit number stamped or laser etched onto the block at the vehicleassembly plant. If reading the identification number the following information canbe obtained:The firs ...