A 1950 1/2 Ton should have Huck brakes. Here is a discussion about a very similar problem on my 38 Master Huck brakes, which are almost identical to the 1/2 Ton. It shows the solution in my case.
Brake problem thread on the VCCA The front shoes does most of the work when moving forward. By the way there is an adjustment for each shoe on the wheel cylinder.