Hi guys,
Went to your intro page and read your story - nice. Looking at the pictures of your rear it appears to me to be changed from original. The original driveline on those trucks was completely enclosed (called a torque tube). There is only one U-joint at the front - none at the rear. The cover on the original rear is round - yours is not. I'm not sure what you've got, but the numbers you've uncovered should be able to narrow it down. That's probably why you're scratching your head about the e-brake setup. Somebody on this site surely will recognize what you've got. This isn't necessarily a bad thing, since it was probably changed to get a better gear ratio for higher road speed. The old rears all were 4:11, which topped you out around 50ish. Now you can get 3:55 ring and pinion to fit the old housing, but that wasn't always the case, so people would change out the rear to get a better gear ratio.
A suggestion: as you're taking things apart, take LOTS of pictures! They will be invaluable on reassembly for stupid little things like, "Did this bolt face in or out?" I also would occasionally draw a diagram. I kept a log book on repairs that I could refer back to and that frequently answered a question or jogged my memory.
Another comment about using the old, single reservoir master with DOT3 fluid. It will require some maintenance to be safe. That brake fluid is hygroscopic (attracts water). Even in a dry climate like yours, I'd recommend bleeding your system every two years - easy with 2 folks, doable with one. Cheap too - costs next to nothing for brake fluid. This will keep the brakes at optimum performance. This is, of course, in addition to frequently checking adjustment and inspecting for leaks.
A tip about installing new brake lines: buy a flare wrench that will fit your fittings at the wheel cylinders and junction blocks - probably a 7/16". Rather than a regular open end (where it's really easy to round off the fitting corners trying to get them tight) the flare wrench has a notch big enough to fit around your brake line but wraps around the nut further giving you more leverage when you tighten. Don't go crazy tightening them initially - you can strip the fittings. As you start to get fluid in the system you'll start chasing leaks and that's when you bear down a bit harder, in my experience (did a '51 GMC full brake system a few years ago). Google "brake line wrenches" and you'll see pictures - that money is well-spent.
Last suggestion: buy a shop manual. They're cheap and can really help you out sometimes. Other times they'll leave you cussing when they call for a specialty tool that hasn't been around for 50 years. You'll find that a lot of old truck repair requires creative problem solving - for example I use a PVC plumbing joint to drive in rear axle oil seals - cost me a buck, works perfectly and is exactly the right size.
Best of luck - you're in the right place to ask questions and get info. Never would have got the '51 running and driving without these folks.
David
Last edited by David Bush; 11/28/2014 5:51 PM.
