GMC Yukon 2000–2006

▸Known issuesHydro-boost brake assist and power steering share one hydraulic supply (four campaigns)2

1. Recall2006 GMC YUKON ・ 2005-05-10

   Power Steering Hose Fracture

   1. 1Fault

      • Leak
      • Smoke or fire
      • Under extreme steering maneuvers, such as turning the steering wheel fully left or right while braking, the hose may fracture and leak fluid; power steering assist would be lost and steering effort would increase.
      • On vehicles with hydro-boost power brakes it could also result in loss of power brake assist and increased braking effort; if the fluid sprays onto hot engine parts, an engine compartment fire could occur.
      • With the Hydroboost braking system, braking assist will be limited to the reserve power assist system; the braking systems on vehicles without Hydroboost are unaffected.
      ↓→

   2. 2Finding the cause

      • Power Steering Line: broken

      Possible causes

      • The high pressure power-steering hose was manufactured with an incorrect compound, making it susceptible to high pressure failure at the elevated fluid temperatures and pressures that can occur during simultaneous braking and steering inputs.

      Steps to confirm (in the document’s order)

      1. Inspect and record the date code on the power steering pressure line; it is printed on the hose and repeated approximately every 6 inches (150 mm).
      2. Vehicles with the hydro-boost system have two hoses to inspect, others only one; the conduit may have to be removed to read the date code.
      3. The suspect date codes are 07135F-2 and 07145F-2; if the hose carries one of them, it must be replaced.
      ↓→

   3. 3Correction

      • Power Steering Line: replaced

      Repair

      1. If the date code is not one of the listed codes, replace the conduit if applicable; no further action is required.
      2. For Silverado/Tahoe/Sierra/Yukon/Escalade, hose replacement follows SI documents 756552 (Non Hydro-Boost Pressure line), 651043 (Power Steering Pump to Hydro-Boost Pressure line) and 651019 (Hydro-Boost to Steering Gear Pressure Line).

      Parts

      • Less than 10% of the involved vehicles will require hose replacement; if parts are required, the appropriate hose(s) are ordered from GMSPO.

      Caution

      • This bulletin is a revision to address hoses used to service 1991-2006 vehicles; dealers who ordered these hoses for service are identified in the attachment to the administrative message.
      • Vehicle eligibility should be confirmed through GMVIS before beginning recall repairs; not all vehicles within the breakpoints may be involved.
   Read the sentences of the record

   From the manufacturer’s document

   • Applies to：Applies to certain 2005 Chevrolet Corvette, Silverado and GMC Sierra, and 2006 Buick Rainier, Cadillac Escalade, Chevrolet Corvette, Express, Silverado, Tahoe, TrailBlazer, TrailBlazer EXT, GMC Envoy, Envoy XL, Savana, Sierra, Yukon and HUMMER H2.
   • Applies to：For the 2006 GMC Yukon the VIN breakpoints are 6R104469 through 6R120468.
   • Applies to：Some of the affected hoses were shipped to dealers by GMSPO between July 25, 2005 and August 24, 2005 and could have been used to service 1991-2006 vehicles.
   • Cause：The high pressure power-steering hose was manufactured with an incorrect compound, making it susceptible to high pressure failure at the elevated fluid temperatures and pressures that can occur during simultaneous braking and steering inputs.
   • Condition：Under extreme steering maneuvers, such as turning the steering wheel fully left or right while braking, the hose may fracture and leak fluid; power steering assist would be lost and steering effort would increase.
   • Condition：On vehicles with hydro-boost power brakes it could also result in loss of power brake assist and increased braking effort; if the fluid sprays onto hot engine parts, an engine compartment fire could occur.
   • Condition：With the Hydroboost braking system, braking assist will be limited to the reserve power assist system; the braking systems on vehicles without Hydroboost are unaffected.
   • Confirm：Inspect and record the date code on the power steering pressure line; it is printed on the hose and repeated approximately every 6 inches (150 mm).
   • Confirm：Vehicles with the hydro-boost system have two hoses to inspect, others only one; the conduit may have to be removed to read the date code.
   • Confirm：The suspect date codes are 07135F-2 and 07145F-2; if the hose carries one of them, it must be replaced.
   • Repair：If the date code is not one of the listed codes, replace the conduit if applicable; no further action is required.
   • Repair：For Silverado/Tahoe/Sierra/Yukon/Escalade, hose replacement follows SI documents 756552 (Non Hydro-Boost Pressure line), 651043 (Power Steering Pump to Hydro-Boost Pressure line) and 651019 (Hydro-Boost to Steering Gear Pressure Line).
   • Parts：Less than 10% of the involved vehicles will require hose replacement; if parts are required, the appropriate hose(s) are ordered from GMSPO.
   • Caution：This bulletin is a revision to address hoses used to service 1991-2006 vehicles; dealers who ordered these hoses for service are identified in the attachment to the administrative message.
   • Caution：Vehicle eligibility should be confirmed through GMVIS before beginning recall repairs; not all vehicles within the breakpoints may be involved.

   Cause

   CERTAIN PASSENGER VEHICLES MAY HAVE BEEN BUILT WITH A POWER STEERING HOSE THAT IS NOT TO SPECIFICATION. UNDER EXTREME STEERING MANEUVERS, SUCH AS TURNING THE STEERING WHEEL FULLY TO THE LEFT OR RIGHT WHILE BRAKING, THE HOSE MAY FRACTURE AND LEAK FLUID.

   Remedy

   DEALERS WILL INSPECT THE POWER STEERING HOSE(S) FOR TWO SUSPECT DATE CODES AND REPLACE THEM IF REQUIRED. THE RECALL WILL BEGIN ON OCTOBER 14, 2005. OWNERS MAY CONTACT CHEVROLET AT 1-800-630-2438, GMC AT 1-866-996-9463, BUICK AT 1-866-608-8080, CADILLAC AT 1-866-982-2339, ISUZU AT 1-800-255-6727, OR HUMMER AT 1-800-732-5493.

   Consequence

   IF THIS WERE TO OCCUR, POWER STEERING ASSIST WOULD BE LOST AND INCREASED STEERING EFFORT WOULD BE REQUIRED. ON VEHICLES EQUIPPED WITH HYDRO-BOOST POWER BRAKES, IT COULD ALSO RESULT IN LOSS OF POWER BRAKE ASSIST AND INCREASED BRAKING EFFORT WOULD BE REQUIRED. IF THE POWER STEERING FLUID SPRAY WERE TO SPRAY ONTO HOT ENGINE PARTS, AN ENGINE COMPARTMENT FIRE COULD OCCUR.

2. Recall2006 GMC YUKON ・ 2005-10-07

   Power steering hose fracture risk recall

   1. 1Fault

      • Leak
      • Smoke or fire
      ↓→

   2. 2Finding the cause

      • Power Steering Line: broken
      ↓→

   3. 3Correction

      Not stated

      What the documents say to do

      Hydro-boost brake assist and power steering share one hydraulic supply (four campaigns)

      Confirm

      • Perform the "Power Steering System Test" found in SI and make any necessary repairs based on system diagnosis.

      Repair

      1. Dealers replace the hydro-boost relief valve.
      2. Dealers test the hydro-boost assembly for functional operation and replace it if it fails.

      Caution

      • An inoperative pump raises steering and braking effort but does not completely remove the ability to steer or slow the vehicle.
   Read the sentences of the record

   Cause

   Certain vehicles may have been built with a power steering hose that is not to specification. Under extreme steering manoeuvres, such as turning the steering wheel fully to the left or right while braking, the hose may fracture and leak fluid. If this were to occur, power steering assist would be lost and increased steering effort would be required. On vehicles equipped with hydro-boost power brakes, it could also result in loss of power brake assist and increase braking effort would be required. If power steering fluid were to spray onto hot engine parts, an engine compartment fire could occur. Correction: Dealers will inspect the power steering hose(s) for two suspect date codes and replace them if required.