how do I release a wheel brake on a tecumseh harry s/p mower?

Hi
The label refers to the brake on the engine that stops the engine quickly when the deadmans handle is released. There is no brake on the rear axle just a lever to engage the drive although it was perhaps at the auction because the drive isn,t working properly? The harry lawnmower is very well built and quite heavy hence the drives do tend to wear quite quickly.
Its usualy the little plates in the drive a bit like a car clutch that get thin and dont grip.

Dave tibbles
August 2009