2007 Daihatsu Materia 1.5L Petrol · AF57 YHN

The front subframe carries the engine, transmission, and lower suspension control arms. On UK cars exposed to road salt and speed humps, the large bonded rubber-to-metal subframe isolation bushes degrade, crack, and debond from the steel shells. Simultaneously, moisture trapped around the mounting brackets causes corrosion of the subframe surfaces. This wear introduces unwanted play between the subframe and the monocoque body, degrading steering precision and causing loud clunking when setting off or braking.

The Materia shares its front suspension geometry with the contemporary Toyota bB and Sirion M300. Potholed British road surfaces place heavy stress on the front suspension wishbone rear voided rubber bushes and the anti-roll bar drop links. The rubber bushes perish, tear, and allow the front wheels to shift under braking, causing steering twitchiness, uneven inner tyre wear, and rattling over minor road imperfections.

The factory steel brake pipes running along the floorpan and over the rear axle lack robust plastic protective coating. Constant road wash, salt brine, and damp mud trapped against the floorpan brackets cause the steel pipes to oxidise and pit. If left untreated, severe corrosion thins the pipe walls, creating a serious risk of hydraulic brake fluid rupture under emergency braking. MOT testers frequently issue failure notices for severely corroded brake lines, necessitating copper-nickel (kunifer) replacement pipes.