Md. Code Regs. 11.14.05.03

Current through Register Vol. 51, No. 20, October 4, 2024
Section 11.14.05.03 - Suspension and Alignment
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.

B. Alignment. Inspect axles for broken, damaged, worn, rusted, bent, or modified axle beams, spindles, or mountings that affect wheel alignment, tracking, toe-in, caster, or camber enough to affect vehicle stability.

Procedures:Reject Vehicle If:
Visually inspect axles for broken, damaged, worn, rusted, bent, or modified beams, spindles, or mountings.Any axle beam, spindle, or mounting is broken, damaged, rusted, bent, or modified to the extent that wheel alignment, tracking, toe-in, caster, or camber is severe enough to affect vehicle stability.

Md. Code Regs. 11.14.05.03

Regulations .03 Safety Standards for Trailers adopted effective October 31, 1988 (15:22 Md. R. 2557)