I need some help with an issue I'm having with the brakes on my 1952 GMC 354-24. For some context, I bought this truck a few years back from a farmer in Montana who was using it to haul grain all the way up until the fall of '23. When it was pulled out the next spring after being stored for the winter, the brakes would not work.
Here is what I have found:
- the brake pedal goes all the way to the floor when initially pressed - pumping the brakes builds pressure allowing the pedal to become firm, however after a minute, the pressure bleeds off and the pedal goes to the floor again - with the engine running, doing the above procedure would cause the motor to bog down a little bit before returning to idle - there does not appear to be any brake fluid leaking from the brake drums, lines, master cylinder, or booster
This leads me to believe that it may be a vacuum issue. Mostly everything mechanical-wise appears to be original and the motor is a 248 ci. I have not taken the wheels off yet to inspect the wheel cylinders. This is the first restoration project that I've owned and are learning as I go along. I wanted to see if anyone has had a similar issue or knows what may be happening before I start throwing parts at it.
