It has manual brakes and has never stopped very well. It has plenty of stiff peddle, has the best wagner pads and shoes you can get and the hardware is in good shape. My great grandfather bought this truck new and I know all of the history. Can someone give me any ideas why or anything to do to get it more efficient.

Does it have discs up front? Are you running stock size wheels and tires? The bigger and heavier those get, the more the brakes have to work. If you have bigger wheels and tires, I'd recommend bigger brakes.

Tim.

discs up front, drum rear and everything is stock, wheels, hub caps and all. If you stand on the brakes, the rears will lock up. My dad and I have been wondering if the discs apply hard enough and if not what do we do.

Assuming that everything is still original, the first thing I'd look at would be the hoses between the frame and calipers. They tend to swell shut over time, and you may not be getting fluid to the front brakes as a result. The same goes for that hose between the frame and rear axle. You won't see it from the outside. You'll have to pull the banjo bolt and check for fluid flow. Replace the copper gaskets with new ones.

Most trucks built in 72 were used as trucks. That means the undercarriage may have been taken a beating from gravel roads and pastures. I'd inspect every line underneath the truck along the entire length of the frame to look for any lines that may be crushed.

Last, make sure the master cylinder is the correct one for non-power disc brakes.

Randy has wise advice.

Only thing I would add is to make sure the lines are properly bled. They may have had air trapped for quite some time and felt like a good peddle all along, but a hydraulic system HATES air.

My dad drove this truck every day for 16 years until he got another truck and we started a mild overhaul/ resto on it 2 years ago. It has always been hard to stop from the day my great grand father drove it off the lot, dealer never found a problem. The master cylinder is OE and we have been thinking about it being the problem. The flex lines have been replaced a few times. We know we have a problem because the 69 and 71 we had stopped fine. Is there a way to identify a power and manual master cylinder?

manual master has the same size reseivor front and back. On the power master one is bigger than the other.

The master cylinder has different size reseivors and it is the mc that came frome the factory. I'm going to check out some replacement cylinders and see what I come up with.