Code of Maryland Regulations › Title 11 - DEPARTMENT OF TRANSPORTATION › Subtitle 14 - MOTOR VEHICLE ADMINISTRATION-VEHICLE INSPECTIONS › Chapter 11.14.05 - Safety Standards for Trailers › Section 11.14.05.03 - Suspension and Alignment

Current through Register Vol. 51, No. 14, July 12, 2024
A.
				Suspension. Inspect the suspension system for missing, broken, damaged, worn,
				rusted, or modified wheel bearings, springs, or frame that would affect vehicle
				stability.
(1) Wheel Bearings. Wheel bearings
				out of adjustment can cause wander, unequal brake action, and noise due to
				interference of parts.
Procedures:
Reject Vehicle If:
Wheel Bearings: With the vehicle lifted, grasp the tire
						  top and bottom and rock it in and out. To verity that any looseness detected is
						  in the wheel bearing, notice the movement between the brake drum or disc and
						  the backing plate or splash shield.
Wheel bearings are loose, rough, galled, or otherwise
						  defective.
(2)
				Springs.
Procedures:
Reject Vehicle If:
With vehicle on a level surface, visually inspect the
						  heights of the four corners of the vehicle. If necessary, use a measuring
						  device and determine differences from side to side. Visually inspect for broken
						  or damaged spring leaves. Inspect spring shackles, bushings, and U-bolts.
(a) Any spring, main, or torque leaf is broken. (b) Any
						  spring with more than four leaves has two or more broken leaves. (c) Any spring
						  with four or less leaves has a broken leaf. (d) Any spring center bolt is
						  broken.
(e) Shackles or U-bolts are missing, broken, worn, loose,
						  or extended.
(f) U-bolts are not of sufficient length to protrude at
						  least 1/4 inch beyond nut when tightened.
(g) Any object or equipment extends below the bottom edge
						  of wheel rim.
(h) Frame is rusted, broken, or damaged, or axle mounting
						  points are rusted, broken, or damaged to affect suspension or axle mounting; or
						  the frame has been repaired and not fishplated; or the body is not attached
						  securely to the frame.
(3)
				Air Suspension. Some trailers and semitrailers may be equipped with air
				suspension systems. Inspection of the system consists of checking for air
				leaks, proper height, and ride level. CAUTION: The inspector should not use a
				creeper under the vehicle unless the vehicle is properly jacked and supported.
Procedures:
Reject Vehicle If:
(a) With entire system drained of air, and while
						  observing the brake air pressure gauge of the towing vehicle, determine
						  pressure at which air begins to lift the vehicle. Pressure regulator valve
						  should not allow air into the suspension system until at least 55 psi is in the
						  braking system.
(a) Air begins to lift the vehicle before 55 psi is
						  indicated on the pressure gauge. (b) Air leakage rate is greater than 3 psi in
						  5 minutes. (c) Vehicle is resting on one or both axles or the vehicle is not
						  level (is listing to right or left).
(b) With air system at normal operating pressure, inspect
						  hoses, connection, and bellows for leaks and excessive deterioration (apply
						  service brakes fully).
(c) With air at normal operating pressure, observe height
						  and level of vehicle relative to ground surface (this will indicate function of
						  pressure regulator and height control valves).
(4)
				Shock Absorbers (if equipped).
Procedures:
Reject Vehicle If:
(a) With vehicle on level surface, push down on each
						  corner of the vehicle and release (if possible).
(a) Vehicle continues free rocking motion for two cycles
						  after release, or shock absorbers are worn, damaged, or leaking to the extent
						  vehicle stability is affected.
(b) With vehicle jacked, visually inspect for missing,
						  broken, loose, or damaged shock absorbers, mounting brackets, bolts and
						  bushings, and excessive leakage.
(b) Shock absorbers, mounting bolts, or mounts are
						  missing, broken, or loose.
(c) Severe leakage (not slight dampness) is present.
(d) Any bushing is missing any portion of the bushing or
						  is damaged, deteriorated, or dry rotted to a point that the bushing is broken
						  or loose.