Express 3/4 Ton Van V8-4.8L VIN V (2003)
Technical Service Bulletin # 04004
Date: 040601
Recall - Brake Hydroboost Relief Valve Seal Defect
File In Section: Product Recalls
Bulletin No.: 04004
Date: June 2004
F/CMVSS NONCOMPLIANCE RECALL
SUBJECT:
BRAKE HYDRO-BOOST RELIEF VALVE SEAL FRACTURE
MODELS:
2003-2004 CADILLAC ESCALADE, ESCALADE EXT, ESCALADE ESV
2003-2004 CHEVROLET SILVERADO, AVALANCHE, SUBURBAN, EXPRESS
2004 CHEVROLET TAHOE
2003-2004 GMC SIERRA, YUKON, YUKON XL, SAVANA
CONDITION
General Motors has decided that certain 2003 and 2004 model year Cadillac Escalade, Escalade EXT and Escalade ESV; Chevrolet Silverado,
Avalanche, Suburban, and Express; GMC Sierra, Yukon, Yukon XL, and Savana; and 2004 model year Chevrolet Tahoe vehicles fail to conform to
either Federal/Canada Motor Vehicle Safety Standard 105, "Hydraulic and Electric Brake System", or Standard 135, "Light Vehicle Brake Systems".
These vehicles may have a relief valve bore within the brake hydro-boost module that is not to specification. An out-of-specification bore could result in
fracture of the relief valve 0-ring seal within the module. If this happens, during braking applications the driver may be able to hear an engine
compartment noise similar to the sound that occurs when the steering wheel is turned to a full stop position. The driver could also experience a slight
increase in steering efforts while braking and parking. Under certain driving conditions, a fractured seal may require a slight increase in the applied brake
pedal effort to achieve the same vehicle deceleration rate as prior to the seal fracture. If this were to occur, it could result in a vehicle crash without prior
warning.
CORRECTION
Dealers are to inspect the hydro-boost module, and replace the relief valve, if necessary.
VEHICLES INVOLVED
