I replaced the entire brake system on my 1953 Model 6400. The rear end is out of an earlier truck, but I finally found the proper brake cylinders. I installed all new lines, wheel cylinders, master cylinder and Hydravac. For some reason I can not get the brakes to pump up. I can't find any leaks, so I assume there must be air in the system, but I have been around it a number of times, including the Hydravac, with no luck. What am I either not doing, or doing wrong? I do not have the motor back in the truck yet so I have not had any vacuum on the system. Could that be the problem?
