Good Morning John.
Sounds to me that it is working right.
Just like head lights, pull the knob out and the lights come on.
Push it in turns them off.
On our "67" 9500, the parking brake is on the steering colume, about a 6" lever. Easy to bump the lever when you climb in or out. I'd rather it be a knob on the dash.

Don

1967 GMC 9500 Fire Ladder Truck
"The Flag Pole"
In the Stovebolt Gallery
1946 2-Ton grain truck
1946 3/4-ton pickup,
1953 1-ton pickup
1957 1-ton flatbed dually,
1954 Pontiac Straight Eight
Of all the things I've lost in my life, I miss my mind the most!