[CR]asbestos in automobile brakes

(Example: Component Manufacturers:Ideale)

Date: Fri, 14 Feb 2003 11:38:33 -0600
To: classicrendezvous@bikelist.org
From: "David Cooper" <dbcooper@rcn.com>
Subject: [CR]asbestos in automobile brakes

Asbestos was added to brake shoes (and clutch discs) for three reasons: 1) because it could take the high frictional heat without disintegrating; 2) because it was abrasion resistant it would not wear out quickly when rubbed against steel; and 3) because it was soft enough to wear out before the brake disc or drum. Altogether asbestos was a great addition to brakes. It was also commonly used for its abrasion resistant properties in floor tile. Asbestos was a fiber and could be woven or processed in many different ways before it was molded into the brake pads or floor tiles.

The problems came up when the asbestos turned into dust which happened as a consequence of wear. The dust is highly toxic. The modern substitutes (for cars) are metal impregnated which is a harder material and therefore does not work as well and it wears the brake discs more quickly, but it does not cause the health problems. Brake systems have largely been re-engineered to compensate for the properties of the modern brake pad materials.

David Cooper
Chicago, IL