Adjuster for drum brakes

An automatic adjuster for an internal shoe drum brake having a strut (not shown) extending between the shoes (11) includes an adjustment element (22) with an edge (24) against which one end of the strut abuts, adjustment of the element (22) maintaining the appropriate clearance between the brake shoes (11) and the drum. The adjustment element (22) has a portion (26) screw-threadedly engaged with a ratchet wheel (29). A pawl assembly (30, 36), associated so with said ratchet wheel (29), moves tangentially with respect to the ratchet wheel (29) as the brake shoes (11) move upon service braking, so that if movement of the brake shoes (11) is in excess of a predetermined amount, a pawl formation (38) will engage a tooth (57) of the ratchet wheel (29) to rotate the ratchet wheel (29) and adjust the adjustment element (22). A temperature sensitive element (60) is provided to vary the ratio of movement of the pawl assembly (30, 36) to movement of the brake shoes (11), so that as the temperature increases the ratio decreases.