From: utzoo!decvax!harpo!seismo!hao!cires!harkins
Newsgroups: net.auto
Title: brakes
Article-I.D.: cires.1974
Posted: Wed Jan 19 09:50:48 1983
Received: Mon Jan 24 01:16:56 1983

bill cox is right: the proportioning valve appeared with the disc/drum
combo; the locking up type situation is what demanded their use in
the first place; gm just did a lousy job of engineering i'd say
and/or they used a valve designed for a different weight distribution
than the x-cars happened to have  ernie harkins