The wear of friction pair is the main reason for the deterioration of braking state. Kutsutsana kumagwira ntchito mwanjira yamphamvu kwambiri, ndipo kuwonongeka kwa zinthu kumawonjezeka pang'onopang'ono ndi kuchuluka kwa kuchuluka kwa ntchito. Kuvalidwa kumadziunjikira pamlingo wina, magawo a mawonekedwe amphamvu pa intaneti pang'onopang'ono amasintha ndipo mphamvu yogwira ntchito imachepetsedwa. The wear of other matching parts also affects the wear of friction pairs. Mwachitsanzo, kuvala kosasinthika kwa kampu ya Brake komwe kumakhudza kukweza kwa cam, yomwe kumakhudza kusamutsidwa kwa nsapato mpaka kumakhudza kulumikizana pakati pa nkhaniyo ndi awiriwo.

Wear depends on the conditions of friction and the state of friction. Zinthu zotsutsana ndizomwe zimakhala ndi mikangano youma, ndipo mawonekedwe a mikanganoyi popanda kuthira mafuta osokoneza bongo, omwe angapangitse kuvala nsapato zofananira. Ndipo munthawi zambiri, kuvala kwa mikangano ndi kuvala kosagwirizana, ndipo kuvala nsapato zoyambitsidwa ndi kuvala konse kulinso, komwe kumadziwika pa Drum Brake. The non-uniformity of friction changes the distribution of brake pressure and increases the non-uniform wear of friction pairs. Kuphatikiza apo, kuwombera nyimbo za kubisalako komanso fumbi la malo ogwiritsira ntchito kusokonekera, komwe kumavala midzi, kuvala kosangalatsa, kuvala kosatheka. Komabe, kuchuluka kwa kuvala kumatha kulamulidwa, chifukwa kuthamanga kwa kuvala kumadalira kuchuluka komanso kuchuluka kwa ntchito, kugwiritsidwa ntchito kwa ntchito, kugwiritsa ntchito komanso kuchuluka kwa ntchito.