This bulletin applies to 2020 Toyota Yaris HB and 2016-2020 Yaris SD vehicles built in Mexico. Some vehicles may exhibit a squeal/squeak noise from the rear during brake application. The cause of this condition is an insufficient amount of grease on the mounting points and backing plates of the rear brake assemblies.
Remove the rear brake drum and shoe assemblies. Confirm that there is sufficient grease present on the assemblies. If not, apply grease to the three ledge surfaces of the backing plate while lifting the brake shoes. Grease can be applied with a cotton swab. Apply grease to the bottom side of the brake shoe anchor points.
Reinstall and road test.