Pretrip Inspection and Daily Maintenance 35.10 Check straight hose installations (those hoses that do not bend along their routings). Pressure changes can cause a hose to lengthen up to two percent, or shorten up to four percent. A 100-inch (2540-mm) length of hose, for example, can contract to 96 inches (2440 mm). If the hose has no slack when it is exhausted of air, replace it with one of adequate length to avoid a possible blow-off from the fitting during vehicle operation. WARNING Do not operate the vehicle with underinflated or overinflated tires.
Incorrect inflation can stress the tires and make the tires and rims more susceptible to damage, possibly leading to rim or tire failure and loss of vehicle control, resulting in serious per- sonal injury or death. 37. Check the tire inflation pressures, and inspect each tire for bulges, cracks, cuts, and penetrations. 35.11 Check for kinked or twisted hoses. A seven- percent twist in the hose can reduce its life by up to 90 percent. Also, a twisted hose under pressure tends to untwist. This could cause it to loosen the fitting. Reconnect hoses that are twisted. IMPORTANT:
The load and cold inflation pres- sure must not exceed the rim or wheel manu- facturer’s recommendations, even though the tire may be approved for a higher load or infla- tion. Some rims and wheels are stamped with a maximum load and maximum cold inflation rating. If they are not stamped, consult the rim or wheel manufacturer for the correct tire infla- tion pressure for the vehicle load. If the load exceeds the maximum rim or wheel capacity, the load must be adjusted or reduced. 36. Make sure the brakes are adjusted on all axles. Adjust the brakes if necessary. See Group 42 of the Cargo Maintenance Manual for checking and adjusting procedures. IMPORTANT:
Brake checking and adjusting is nec- essary for all vehicles, including trucks equipped with automatic slack adjusters. 37.1 Check the inflation pressures of the tires be- fore each trip using an accurate tire pres- sure gauge ( Fig. 9.5 ). Tires should be checked when cool. Be sure the valve stem 9.18