Special nut and washer set for brake expanders.

Special nut and washer set for brake expanders.

These are for mechanical rear brakes as fitted to ACs from 1947 to early 1951.

They secure the brake expanders to the rear back-plates, but allow them to 'float'. The expanders need to be able to slide against the back-plates. If the nuts are (wrongly) fully tightened, the brake force will be reduced.

These special thin self-locking nuts (5/16 BSF), should not be fully tightened. Double coil spring washers are fitted under the nuts, to pre-load the expanders.

The nuts come from an aero-space company, hence they are not cheap.

Ideally, the expanders should be lightly greased (between body and back-plate) with a suitable mechanical brake grease (colour coded green or blue). Avoid any grease that will release oil onto the brakes when warm. Red rubber grease is not suitable for metal-to-metal lubrication.

Price is for the set (new)