Advertisement
If you have a new account but are having problems posting or verifying your account, please email us on hello@boards.ie for help. Thanks :)
Hello all! Please ensure that you are posting a new thread or question in the appropriate forum. The Feedback forum is overwhelmed with questions that are having to be moved elsewhere. If you need help to verify your account contact hello@boards.ie
Please note that it is not permitted to have referral links posted in your signature. Keep these links contained in the appropriate forum. Thank you.

https://www.boards.ie/discussion/2055940817/signature-rules
Hi there,
There is an issue with role permissions that is being worked on at the moment.
If you are having trouble with access or permissions on regional forums please post here to get access: https://www.boards.ie/discussion/2058365403/you-do-not-have-permission-for-that#latest

NCT - Brake Ovality Failure

  • 10-05-2013 1:10pm
    #1
    wandererz
    Registered Users, Registered Users 2 Posts: 2,857 ✭✭✭


    NCT failure on ovality.

    Would this be the shoes or drums?

    Also, been quoted some crazy (and widely differing) prices for replacement of rear drums and shoes on a Focus.

    Any idea what this should cost from your experience?


Comments

  • #2
    jimgoose
    Registered Users, Registered Users 2 Posts: 20,196 ✭✭✭✭jimgoose


    Wear/scoring of the drums, most likely. What year/mileage? You should be able to get a pair of drums for it for under €100, and a couple of hours at most to replace.


  • #3
    CiniO
    Registered Users, Registered Users 2 Posts: 16,069 ✭✭✭✭CiniO


    Could anyone tell me what "ovality" means in relation to brakes?
    I never could understand this term...


  • #4
    jimgoose
    Registered Users, Registered Users 2 Posts: 20,196 ✭✭✭✭jimgoose


    CiniO wrote: »
    Could anyone tell me what "ovality" means in relation to brakes?
    I never could understand this term...

    Ovality is the difference in braking force measured during one rotation of the wheel. It is indicative of worn drums and damagaed or "warped" rotors.


  • #5
    biko
    Registered Users, Registered Users 2 Posts: 81,219 ✭✭✭✭biko


    Afaik it simply means "not perfectly round/is warped" depending on if it's drum or disc.
    Both can become disfigured by overheating/cooling down too fast/other.


  • #6
    jimgoose
    Registered Users, Registered Users 2 Posts: 20,196 ✭✭✭✭jimgoose


    biko wrote: »
    Afaik it simply means "not perfectly round/is warped" depending on if it's drum or disc.
    Both can become disfigured by overheating/cooling down too fast/other.

    Actual disc "warping" is rare, especially with ductile iron rotors. What does happen though, is when you get the brakes nicely hot, as in braking down nice and lively from some speed, then leaving the brakes on hard after coming to a stop. This permanently deposits a thin layer of pad material onto the rotor, and eventually the resulting slight variation in thickness accelerates the process. Eventually, the internal ferrite structure of the disc is altered.


  • Advertisement
Advertisement