gregory bender

http://www.thisoldtractor.com/gtbender

Brake actuation rod (for the rear brake)

In early February of 2009, Joe Cox contacted me asking about the brake actuation rod. I sent him some measurements and photos of my original, and then he crafted one.

Gregory Bender's notes

The brake actuation rod connects the brake pivot to the brake actuation arm on the brake plate. It is made of 6 mm rod, bent at 90° at one end (to fit through the brake pivot) and threaded at the other end (6 mm x 1 mm) to accept the adjustment nut.

I'd use 6 mm Stainless Steel rod. A bit more difficult to bend and thread, but it can be polished and will never rust. McMaster-Carr sells it; search for item number 1274T15.

If you don't have the nut, this one from McMaster-Carr would work: 90368A300. Just bevel the bottom and have it push up against a short length of cross drilled rod of larger diameter.

Key measurements:

• Length from inside corner of the bend to the end of the threads: 455 mm
• Length of bent end from the inside corner of the bend: 10 mm
• Approximate Length of threads: 50 mm - 60 mm
• The short little cross-rod that the knurled nut runs up against is made of 12 mm diameter rod. Instead of buying a entire length of rod, I'd just buy a 12mm bolt that wasn't fully threaded and make it out of that.

I'd drill a hole for the cotter pin, stick 10 mm in the vice and bend it 90°. Measure 455 mm to the end and cut it off. Thread the end to 50 mm (or so) and call it good.

A couple of notes:

1. Use a washer between the cotter pin and the pivot arm to prevent wear and breakage of the cotter pin.
2. If you look at the photos carefully, you'll notice the original design had corresponding "V" notches cut/filed into the knurled adjustment nut and the corresponding very short cross rod. This "V" notch is nothing more than a locking mechanism to prevent the nut from coming loose, etc. Be sure to add one of your own.

90 degree bend at the forward end of the rod (I'm in the middle of experimenting to get more feel with my 850T brake drum).

Cross rod and adjustment nut (850T brake drum shown).

Cross rod and adjustment nut (850T brake drum shown).

Cross rod and adjustment nut (850T brake drum shown).

Joe Cox's notes

Overall the fabrication of the brake rod was easy. There are a few things that should be noted:

1. All of the parts ordered from McMaster-Carr were perfect and they arrived within 24 hours - I was impressed!
2. I recommend that you cut the rod you get from McMaster-Carr into two equal sections before you start the project
   1. It's a long rod and a shorter rod is easier to work with.
   2. Plus it's nice to have a second "blank" just in case you screw the first one up (like I did)
3. Before you start to thread the rod, bend the end that goes through the brake lever first
   1. To bend the stainless steel rod - you must apply heat to the area that you plan to bend. I used a little propane torch to do this.
4. I recommend that you taper the tip of the rod a little, before you apply the threading tool (dye)
   1. I used my bench grinder to taper the end a little.
5. I also recommend that you apply a little bit of grease to part of the rod you plan to thread. This will ensure "good deep threads" are created.
6. Rather than use a "bolt" for the "cross rod" - I found a short Clevis Pin at Ace Hardware that worked great.

It's a very nice setup and should work fine for years!

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