23-028-VEH: OOSC, Parte II, Artículo 1. sistemas de frenos, a. (5) Frenos de aire de tambor, (a) Casquillo faltante

Fecha de registro	12 de julio de 2023
Número de asunto	23-028-VEH
Nombre	Eric Sundby
Agencia	MN State Patrol
Dirección	1110 Centre Pointe Curve, Suite 410Mendota Heights, Minnesota, 55120United StatesVer en el mapa (se abre en una pestaña nueva)
Teléfono	12183960866
Correo electrónico	[email protected]
Comité	Comité de Vehículos
Estado	Cerrado
Resumen del asunto	Casquillos de leva en S faltantes
Justificación o necesidad	En una de las fotos incluidas, el árbol de levas está golpeando contra el tambor, lo que afecta el funcionamiento del freno. Estaba ajustado, pero debido a que el árbol de levas golpeaba contra el tambor, se interrumpía el recorrido del freno.
Solicitud de acción	Incluir la ausencia total de cualquier buje del árbol de levas en la regla del 20%, junto con otros componentes que falten o estén rotos.
Medidas adoptadas por el comité	The request is to add 20% brake defect criteria for the S-cam bushing missing. This situation likely resulted in another underlying issue aside from the missing bushing. A question was raised as to whether braking performance would be affected due to a brake application and the centering of the camshaft when the pads touch the drum. The committee discussed that a missing bushing would be like other brake components identified in the out-of-service criteria and should be included as a brake defect and in the 20% brake calculation. There were pictures of three different brakes shown, and in some cases, there were no other brake defects present. Whether or not brake performance is affected would not determine if a brake assembly has a defect and should be repaired. Inclusion as a 20% defect does not automatically place the vehicle out-of-service. An amendment to the 20% OOS condition to add a condition for the S-cam bushing missing in Part II, Item #1.(5)(a) was made. Discussion about brake effectiveness and how a missing bushing would affect performance. 1. Brake Systems a. Defective Brakes (5) Drum (Cam-Type and Wedge) Air Brakes Missing or broken brake shoe, lining, return spring (shoe or chamber), anchor pin, spider, cam roller, camshaft, camshaft bushing (missing only), pushrod, yoke, clevis pin, clevis pin retainer (e.g., cotter pin), brake adjuster, parking brake power spring or air chamber mounting bolt. The “2006-01, Camshaft bushing” inspection bulletin would also need amended due to the edit to the OOSC. Discussion to amend the wording of the document to only apply to worn bushings and align with the OOSC criteria change. A change was also made to rename the bulletin from “Camshaft Bushings” to “Worn Camshaft Bushings” with edits to refer to worn bushings only.(This bulletin amendment would be dated for April 1, 2024 to correspond with the change in the OOSC)
Documentos de respaldo	Missing-S-Cam-Bushing-3.JPG (se abre en una pestaña nueva) Missing-S-Cam-Bushing.jpg (se abre en una pestaña nueva) Missing-S-Cam-Bushing-2.JPG (se abre en una pestaña nueva) IMG_2596.JPG (se abre en una pestaña nueva)

Fecha de registro

12 de julio de 2023

Número de asunto

23-028-VEH

Nombre

Eric Sundby

Agencia

MN State Patrol

Dirección

1110 Centre Pointe Curve, Suite 410Mendota Heights, Minnesota, 55120United StatesVer en el mapa

Teléfono

12183960866

Correo electrónico

[email protected]

Comité

Comité de Vehículos

Estado

Cerrado

Resumen del asunto

Casquillos de leva en S faltantes

Justificación o necesidad

En una de las fotos incluidas, el árbol de levas está golpeando contra el tambor, lo que afecta el funcionamiento del freno. Estaba ajustado, pero debido a que el árbol de levas golpeaba contra el tambor, se interrumpía el recorrido del freno.

Solicitud de acción

Incluir la ausencia total de cualquier buje del árbol de levas en la regla del 20%, junto con otros componentes que falten o estén rotos.

Medidas adoptadas por el comité

The request is to add 20% brake defect criteria for the S-cam bushing missing. This situation likely resulted in another underlying issue aside from the missing bushing. A question was raised as to whether braking performance would be affected due to a brake application and the centering of the camshaft when the pads touch the drum. The committee discussed that a missing bushing would be like other brake components identified in the out-of-service criteria and should be included as a brake defect and in the 20% brake calculation. There were pictures of three different brakes shown, and in some cases, there were no other brake defects present. Whether or not brake performance is affected would not determine if a brake assembly has a defect and should be repaired. Inclusion as a 20% defect does not automatically place the vehicle out-of-service.

An amendment to the 20% OOS condition to add a condition for the S-cam bushing missing in Part II, Item #1.(5)(a) was made. Discussion about brake effectiveness and how a missing bushing would affect performance.

1. Brake Systems a. Defective Brakes (5) Drum (Cam-Type and Wedge) Air Brakes Missing or broken brake shoe, lining, return spring (shoe or chamber), anchor pin, spider, cam roller, camshaft, camshaft bushing (missing only), pushrod, yoke, clevis pin, clevis pin retainer (e.g., cotter pin), brake adjuster, parking brake power spring or air chamber mounting bolt.

The “2006-01, Camshaft bushing” inspection bulletin would also need amended due to the edit to the OOSC. Discussion to amend the wording of the document to only apply to worn bushings and align with the OOSC criteria change. A change was also made to rename the bulletin from “Camshaft Bushings” to “Worn Camshaft Bushings” with edits to refer to worn bushings only.(This bulletin amendment would be dated for April 1, 2024 to correspond with the change in the OOSC)

Documentos de respaldo