GMC Yukon 2000–2006

▸Known issuesHydro-boost brake assist and power steering share one hydraulic supply (four campaigns)1

1. Manufacturer communication2003–2006 GMC YUKON DENALI ・ 2018-06-11(2 earlier editions of this document folded here)

   Power steering pump and line replacement procedure

   1. 1Fault

      • In rare cases there is a lack of steering assist when stopped or during parking lot type maneuvers.
      • The condition goes away or greatly improves once the vehicle begins to move or is above parking lot speeds.
      ↓→

   2. 2Finding the cause

      Possible causes

      • The concern can be aggravated by worn tires, low tire air pressure, low power steering pump pressures, and tires larger than stock size.

      Steps to confirm (in the document’s order)

      1. Perform the "Power Steering System Test" found in SI and make any necessary repairs based on system diagnosis.
      2. To tell whether a 670 gear box is fitted, inspect the mounting bolts that attach the stub shaft housing; a 670 gear box has only 3 mounting bolts.
      ↓→

   3. 3Correction

      • Line: replaced
      • Power Steering Pump: replaced

      Repair

      1. If a C/K 1500 Series vehicle is equipped with a 670 gear box, replacing it with a 680 gear box may increase the customer satisfaction.
      2. When replacing a 670 gear box with a 680 gear box, replace the power steering gear, union fitting and both inlet O-ring seals.

      Parts

      • Parts (C/K 1500 series only): 88965542 Power Steering Gear, 26025709 Union Fitting, 26001594 Inlet O-ring Seal.

      Part numbers printed in the document

      • 88965542Gear, Steering (Remanufacture)Look up at RockAuto (aftermarket candidates) ↗Search the web ↗

        Replaced by: 19330495as stated by GMPartsGiant (checked 2026-10-06) ↗Look up at RockAuto (aftermarket candidates) ↗Search the web ↗

      • 26025709Fitting,P/S PumpLook up at RockAuto (aftermarket candidates) ↗Search the web ↗

        No successor statedas stated by GMPartsGiant (checked 2026-10-06) ↗

      • 26001594Seal,P/S Fluid Cooling Pipe(O Ring)Look up at RockAuto (aftermarket candidates) ↗Search the web ↗

        No successor statedas stated by GMPartsGiant (checked 2026-10-06) ↗

      The numbers are as the document prints them. The name and the replacing number are what the pages of GMPartsGiant, a reseller of genuine parts and not GM, state. Aftermarket equivalents are not checked here (the links only search by number). Confirm the fit for the vehicle (VIN) before ordering.

      Caution

      • For C/K 1500 series vehicles, if diagnostics did not lead to any repair, the concern is a normal operating characteristic.
      • If the stub shaft housing has no mounting bolts or has 4 bolts, do not proceed with this bulletin; the vehicle does not have a 670 gear box.
      • It is recommended in all cases that the proper tire size and the maximum tire pressure are set to the manufacturer's specification on the door placard, especially for the front tires.
   Read the sentences of the record

   From the manufacturer’s document

   • Applies to：The model list names 2003-2006 GMC Yukon, Yukon Denali and Yukon XL.
   • Condition：In rare cases there is a lack of steering assist when stopped or during parking lot type maneuvers.
   • Condition：The condition goes away or greatly improves once the vehicle begins to move or is above parking lot speeds.
   • Cause：The concern can be aggravated by worn tires, low tire air pressure, low power steering pump pressures, and tires larger than stock size.
   • Confirm：Perform the "Power Steering System Test" found in SI and make any necessary repairs based on system diagnosis.
   • Caution：For C/K 1500 series vehicles, if diagnostics did not lead to any repair, the concern is a normal operating characteristic.
   • Repair：If a C/K 1500 Series vehicle is equipped with a 670 gear box, replacing it with a 680 gear box may increase the customer satisfaction.
   • Confirm：To tell whether a 670 gear box is fitted, inspect the mounting bolts that attach the stub shaft housing; a 670 gear box has only 3 mounting bolts.
   • Caution：If the stub shaft housing has no mounting bolts or has 4 bolts, do not proceed with this bulletin; the vehicle does not have a 670 gear box.
   • Repair：When replacing a 670 gear box with a 680 gear box, replace the power steering gear, union fitting and both inlet O-ring seals.
   • Parts：Parts (C/K 1500 series only): 88965542 Power Steering Gear, 26025709 Union Fitting, 26001594 Inlet O-ring Seal.
   • Caution：It is recommended in all cases that the proper tire size and the maximum tire pressure are set to the manufacturer's specification on the door placard, especially for the front tires.

   Open the manufacturer’s document (PDF) ↗ The points above were read from this document.

   Remedy

   This technical bulletin provides a procedure to replace the power steering pump and line to correct the customers concern of lack of steering assit when stopped or parking lot manuvers.