81-87 rear brake circuit have residual check valve stock?

[kipps]

Originally Posted by Hart_Rod

Slightly off topic, but has anyone ever heard of anti-locking rear brakes on an 87? Any information on them? Just noticed it's on my window sticker.

I have an 87 3/4 ton. It came from the factory with a load-control valve above the rear axle. Supposedly under very heavy braking conditions, the rear of the truck would lift up, and would be prone to locking the rear brakes. This valve would close off the rear brake line, and reduce the chance of the rear locking up in these conditions. This valve is commonly removed.

I don't know if the 1/2 tons had the same valve. If so, GM may have called it anti-lock brakes, as a marketing gimmick.

Keith Seymore would know what's meant by "anti-lock brakes", I'm sure.