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Center for Education

Thomas Built Buses

C2 Air disc brakes

Portland, Feb.14th 2008Presenter Name

Security Classification Line

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Air Disc Brakes

•Available on C2 Front and Rear

•Bendix model ADB22X

•Internal automatic brake adjustment allows the brakes to always be in a state of optimum adjustment.

•Straight, stable stops due to minimized brake force variation between brakes.

•Reduced part number complexity

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Air Disc Brakes

• FMVSS 121 is the minimum standard for the stopping distance of a commercial vehicle.

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Air Disc Brakes

•Reduced number of part numbers equal less parts to stock

•Same components equals easier to work on

•Same rotors all the way around

•Same pads front and rear

•Same caliper kits left and right for the front and rear

•Available in a complete loaded caliper for LH or RH for quicker replacements

•Replace brake pads without removing the caliper.

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Air Disc Brakes – Wear Indicator•Visual Inspection of wear indicator

•Visually inspect every 3 months

•Inspect the notch in the caliper and carrier if they line up it is time to remove the wheel for further inspection.

•Notches that line up do not constitute “out of service” criteria

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Air Disc Brakes – Pad Replacement

•Easy replacement brake pads

•No need to remove caliper or rotor

•Recommended to replace in axle sets

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Air Disc Brakes – Pad Replacement

•Release or cage the brakes and support the vehicle with proper jack stands and chock all wheels that remain on the ground

•Prior to pad removal

•Pull of the adjuster cap (37) using the tab, taking care to keep the shear adapter (61) in position on the adjuster (23)

•Using a box-end wrench or socket, fully wind back the tappet and boot assemblies by rotating the shear adapter in a counter-clockwise direction

•Note do not use an open-ended

wrench as this may damage the adapter

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Air Disc Brakes – Pad Replacement

•Remove the clip (26) and washer (45), depress the pad retainer (11) and remove the pad retainer pin (44)

•Discard these four items – replacements are included in the service kit (BW 802078)

•To remove the outer brake pad, slide the caliper fully to the outboard position first.

•To remove the inner pad slide the caliper to the inboard side.

•While you have the pads removed perform a brake rotor inspection

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Air Disc Brakes – Rotor Inspection

•Measure the thickness of the rotor at the thinnest point

•Replace the rotor when the minimum thickness of 1.46 inches or 37 mm.

•Turning the rotors is not normally necessary. In the case of severe grooving of the entire friction surface, however, turning could be useful, and may increase the load bearing surface of the pads.

•The minimum thickness after turning must be greater than 1.53 inches or 39 mm.

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Air Disc Brakes – Rotor Inspection

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Air Disc Brakes

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Air Disc Brakes

Front Rear

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Air Disc Brakes

Service Manual

BW7308

SD-23-7541

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Air Disc Brakes

Parts Manual

BW1114

ADB-0408

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Air Disc Brakes – special tools available

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Air Disc Brakes

•Questions?