Fuel pumped from an underground storage tank is cool but when exposed to a warmer
ambient temperature, will expand. Before controls were mandated, an owner might fill the
fuel tank with fuel from an underground storage tank and park the vehicle for some time in
warm area, such as a parking lot. As the fuel would warm, it would expand and should no
provisions or area be provided for the expansion, the fuel would spill out of the filler neck
and onto the ground, causing hydrocarbon (HC) pollution and creating a severe fire
hazard. To correct this condition, the vehicle manufacturers added overflow plumbing
and/or gasoline tanks with built in expansion areas or domes.
However, this did not control the fuel vapor emission from the fuel tank. It was determined
that most of the fuel evaporation occurs when the vehicle is stationary and the engine is
off. Most vehicles carry 5-25 gallons (19-95 liters) of gasoline. Should a large
concentration of vehicles be parked in one area, such as a large parking lot, excessive fuel
vapor emissions would take place, increasing as the temperature increases.
To prevent the vapor emission from escaping into the atmosphere, the fuel systems were
designed to trap the vapors while the vehicle is stationary, by sealing the system from the
atmosphere. A storage system is used to collect and hold the fuel vapors from the fuel
tank when the engine is not operating. When the engine is started, the storage system is
then purged of the fuel vapors, which are drawn into the engine and burned with the
air/fuel mixture.
Summary of Contents for TrailBlazer
Page 1: ......
Page 26: ...Fig 3 Typical body and undervehicle maintenance locations Refer to chart for descriptions ...
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Page 175: ...Spring free length check Valve spring squareness check ...
Page 192: ...Front of piston mark ...
Page 361: ...5 3L Engine Except Saab Underhood Fuse Block 2003 2005 Early Production ...
Page 469: ...Removing the outer band from the CV boot Removing the inner band from the CV boot ...
Page 470: ...Removing the CV boot from the joint housing Clean the CV joint housing prior to removing boot ...
Page 471: ...Removing the CV joint housing assembly Removing the CV joint ...
Page 472: ...Inspecting the CV joint housing Removing the CV joint outer snap ring ...
Page 473: ...Checking the CV joint snap ring for wear CV joint snap ring typical ...
Page 474: ...Removing the CV joint assembly Removing the CV joint inner snap ring ...
Page 475: ...Installing the CV joint assembly typical ...
Page 553: ...9 Torque the lug nuts to specification 10 Lower the vehicle ...
Page 556: ...Toe in Frame Misalignment Frame misalignment ...
Page 588: ...Bleeding caliper ...
Page 624: ...Manifold gauge set components Refrigerant recovery recycling station ...
Page 676: ...A C Specifications ...
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