1950 John Deere BN Brakes - Can You Say Scope Creep?

The brakes on this tractor did work but not very well. Neither brake pedal would spring back like they're supposed to after releasing the brake pedals. Also, the right hand brake was adjusted too tight and was dragging some, so my first order of business was to try and loosen the right side adjuster. It was stuck and did not want to budge one little iota. Ok, so let's pull the brake drum off and see what's going on. That was the first level of scope creep, removing the drum, and it was an hour-long endeavor but the drum is finally off. Come to find out though, that's the least of my worries.

Yep, that there piece of stuff in the drum is half of the very thin remains of one brake shoe lining. A bit more scope creep. For those unfamiliar with the term Scope Creep, it's when a project starts out simple in your mind but ends up being complicated, sometimes very complicated. The scope of work just keeps creeping up and up, and this is one of those times.

I quickly found out that working on the brake while it was still on the tractor wasn't gonna cut it, so it was time to pull the brake assembly off. More scope creep.

This next photo below shows two round steel rods poking out from the casting. They are the adjusting pins for the brake shoes. Both pins plus the adjuster screw are frozen tight in the casting. Time for a little scope creep and some judicious application of heat.....

Yes, I'd say that's judicious. I was able to get one adjusting pin free and out of its bore......

I wasn't so fortunate working on the second adjusting pin. One ear snapped off. Great...

I did manage to get the adjusting screw out with all that heat applied. It's at the bottom of the photo, and is a fairly complicated piece. I'm glad it didn't break.

Here are the two adjusting pins and the screw. Notice that the tapered screw end has slots that the wedged ends of the pins fit into.

Having nothing to lose but time, I decided to try and weld up the broken tab. So far so good.

I used the mini lathe to turn down the built-up weld to the OD of the pin.

I then re-machined a 1/4" slot back into the end of the pin using my Smithy 1340 lathe/mill.

I think it will work. There isn't much sideways force on the tabs. They are only to keep the brake shoes centered in the brake assembly.

Nobody will be able to tell them apart.

Well, a major scope realignment just happened. I broke a part. A rather complicated part that I just can't make. It's called a brake pedal shaft, and it is what the brake pedal attaches to. Most of the shaft's details would be fairly simple to make but it has some tapered splines that would be very difficult.

Here's the story. Things seemed to be going well. The nut was threading off easily. I was able to break the brake pedal splined end free of the pedal shaft using a hydraulic press. I'd left the nut on the threaded part of the pedal shaft to protect the shaft threads, so it was just a matter of unthreading the nut the rest of the way. I got the nut halfway off and it just hit a stopping point. I tried going either way and it wouldn't budge. The only thing I can think happened is the threads became galled but I didn't know that at the time. Well, I thought I could just muscle my way through the tight spot so I got a 24" breaker bar. Unfortunately it lived up to its name and the end of the pedal shaft broke off. Sigh....

I looked online and found one for about $30 but it wouldn't arrive here until after we left on a trip. I figured I could spend the afternoon trying to fix this broken one. I turned down the remains of the threads to a small 3/16" diameter stub.

I then chucked up a piece of 1/2" bar and drilled a 3/16" hole in the end to accept the stub on the pedal shaft. I also tapered the end of the bar so I could lay down some good weld beads.

While at the lathe, I decided to try and get the broken piece of shaft out of the nut. I first drilled out the center of the broken stub, then used a boring bar to shave more and more off the ID of the stub until it threaded itself out.

Back to the pedal shaft. I welded the two pieces together and then turned the weld down to 1/2" diameter.

I then single-point threaded the thing most of the way, then finished it with a 1/2-13 die.

Only time will tell if the weld will hold, but I'm hopeful.

With the brake pedal off its shaft, I found a petrified o-ring supposedly "sealing" the shaft. It was rock hard. So hard in fact that I thought it was a metal ring at first, but it broke when I squeezed it. I found a replacement in my stash of o-rings.

I looked online for replacement lining material and found some but it wouldn't come for at least a week, and I would be gone on said trip so I decided to use up the piece of lining that was left over from my JD LA brake repair. I had to trim 1/4" off its width to get it to the 1-1/2" width I needed.

I clamped the lining to the shoe, then drilled holes for the rivets.

I used a small Forstner bit to countersink and make room for the rivet heads.

I'd made this punch set when I did the LA brake band. It still worked great.

One brake shoe down, one to go. If you notice below, I didn't use the holes in the shoe from the old rivets. I did attempt to, and got so far as to get all the holes drilled and countersunk to match up to the original holes, but the holes in the shoes were too large for the rivets I had on hand, so I had to drill new holes the proper diameter through the brake shoes, then also drill and countersink new holes through the brake band lining. I only messed up the first lining though, and it really wasn't a big deal that there were eight holes that weren't being used.

Things are shaping up. Getting the shoes back on the brake housing was a bit difficult, as the springs were super stiff. I ended up putting on the upper spring on both shoes, then wrestling the assembly onto the housing. I then used a vice-grip pliers to grab one end of the second spring and get it sprung into place.

The brake assembly is back on the tractor and it works very nicely. The pedal even springs back when letting off the brake. It's the small things... I'm not sure I want to delve into the left brake right now. I think I need a bit of a break from brakes.