Ride Height Valve Check
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When removing or loosening a Barksdale height-control valve from a mounting bracket, always hold the valve-side mounting studs in place with an Allen wrench while loosening or tightening the nuts that attach the valve to the bracket. Because the mounting studs are threaded into the valve body, loosening the nuts without holding the studs can tighten the studs, which can crush the valve body and damage the valve. Conversely, tightening the nuts without holding the studs can back the studs out, causing a separation of the two halves of the valve body, and possibly a leak.
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Do not overtighten the bolts in the Barksdale height-control valve housing. The bolts should not be loose, and should not require tightening. Only if necessary, tighten the valve housing bolts 45 lbf·in (500 N·cm). Any damage to the valve housing will void the warranty.
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Do not attempt to disassemble the Barksdale valve body or the control lever. There are no serviceable parts in the valve, and any disassembly will void the warranty.
- Park the vehicle on a level surface, using a light application of the brakes. Do not apply the parking brakes. Shift the transmission into neutral, and build the secondary air pressure to at least 100 psi (690 kPa). Shut down the engine.
- Mark the location of the front and rear tires on the floor, and chock the tires on one axle only.
- Check that the height-control valve vertical linkage is connected and oriented correctly.
- Measure the distance from the axle stop to the top of the
axle U-bolt pad. The correct distance is determined by the axle and
suspension configurations; refer to of the 108SD and 114SD Workshop Manual for details.
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Valve Mounting Bracket
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Height-Control Valve
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Stud Bolt
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Linkage Rod
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Axle
Fig. 1, Typical Barksdale Height-Control Valve Installation (side view)
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- If the axle stop measurement is not correct, see of the 108SD and 114SD Workshop Manual for adjustment procedures.
- Apply the parking brakes, and remove the chocks.
Important: Before checking the AirLiner suspension height, make sure there is no load on the chassis, and the trailer is unhitched.
Notice: To prevent voiding the warranty on Barksdale height-control valves, observe the following:
Note: The stud bolt that fastens the height-control valve horizontal lever to the vertical linkage is oriented correctly when the linkage rod is vertical, as viewed from the side of the vehicle; see Fig.. The rod may be on the forward or aft side of the lever to get it to be vertical.