I have a 1950 3600 so pretty much the same brakes. I just finished mine. You might want to look at the manual also. If you have the orginal 'huck' style brakes, make sure you remove the shoes and ALL the pins and anchors, clean up EVERYTHING and reinstall using some anti sieze. Everything should move free. Also, like suggested above, make sure the wheel cylinders are not leaking. I put a kit in mine. Brake parts (expecially rear) are not easy to come by for our trucks. Be careful if you have the drums truned. I have a spare set of shoes and just have them re-lined. I also used a new master cylinder and no problems. Make sure you adjust the parking brake correctly also. There's an ecentric (spelling) bolt that the parking brake arm pivots on. It must also be ajusted right.
Here's the link to the manual. Hope this helps.
manual
