Brake Drum Question

Discussion in 'Heavy Duty Diesel Truck Mechanics Forum' started by silverspur, Sep 5, 2022.

  1. silverspur

    silverspur Road Train Member

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    At shop to have a chipped brake pad replaced. Mechanic says drum has cracks and should be replaced. I don't know enough about brake drums to know if he is BS ing me or not. 20220905_092502.jpg 20220905_092502.jpg 20220905_091628.jpg
     
  2. kwcam

    kwcam Light Load Member

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    If you are putting new shoes on for sure put a new drum on also.
     
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  3. blairandgretchen

    blairandgretchen Road Train Member

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    I think the general rule is 2 sets of shoes to 1 set of drums.

    Those look pretty bad to me, I’d replace.
     
  4. AModelCat

    AModelCat Road Train Member

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    I've seen worse. Its called heat checking and is a relatively normal occurrence.
     
  5. silverspur

    silverspur Road Train Member

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    They replaced the drum.
    Thanks for the input.
     
  6. BoxCarKidd

    BoxCarKidd Road Train Member

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    Those heat cracks probably do not warrant replacement.
    Drums are marked with a maximum diameter for reuse. Often 16.620 inches ( about 16 and 5/8's ). Does not look like you threw any money away.
     
  7. GYPSY65

    GYPSY65 Road Train Member

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    Can you replace just one drum?

    I’ve always done them all at the same time or at least in pairs
     
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  8. Hammer166

    Hammer166 Crusty Information Officer

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    You could, so long as it's not on the steer. I wouldn't myself, but on the drive or tandem you likely wouldn't notice that one corner was doing a slightly better job than the others. Up front you'd be wrestling the wheel every time you made anything other than the lightest of brake applications.
     
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  9. BoxCarKidd

    BoxCarKidd Road Train Member

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    Only in a bind. That causes unequal braking. That is a bad thing in the rain. Snow and ice are worse.