Earthforce EF-3 Parking Brake
EF-3 operates on hydraulic drive, so needs no service
brakes. Except when I'm stopped on a hill and I need to
move a fence, rock, chair, or other obstacle in front of
me. Then, I need a parking brake so I don't loose the
machine or my legs. However, the cable broke. For a
while, I carried a brick, but I continued to have trouble
dropping it in front of a wheel. I'd have to get off the
machine to relocate the brick. Then I had trouble getting
the brick in front of the machine as it rolled away.
Finally, after ordering another cable from the Bobcat
store for a B200/B250 (the Bobcat remarketed equivalent), I
found the cable is two and three quarter inches longer.
Seems that Bobcat reengineered the mounting postion for
the cable end next to the driveshaft disk brake.
Options: 1) Cut the cable and reweld/braze. 2) Fabricate a new cable mount for the lever end. 3) Fabricate a new cable mount for the caliper end. 4) Move the lever. 5) Retain the brick. I discarded Option 5 as its so hard to use. Having seen Option 4 on a friends machine, I vetoed it as it took too much cutting. Option 2 would be too public a display of my crude workmanship. Option 1 seemed the best way to flush $40. So I took Option 3, fabricating a bracket that moved the cable 2.75" further away from the existing cable stop.
|Here is the main cable holder tube bracket after welding. This is just the tube bracket. There are more parts to come, as I try to make even a moderately simple task twice as complicated. This is a 1/2" steel tube welded on to about seven inches of angle iron (actually steel). I used my great drill press to drill a 7/16 hole at the bottom.|
|Another photo of the main tube on the angle iron. Note the slot ground along the length of the tube. This slot allows easy installation and removal of the brake cable. The old one did not have this and I had to unscrew the cable from the little yoke on the caliper by twisting the entire four foot cable. No huge problems taking it off. But try to line up the cable with the little yoke barrel and twist this four foot cable while holding the screw end on one side, rotating the cable on the other end, and hoping the screw end would engage in the hole. A family member (or interested friend) could have been useful.|
|This is the precision inner cable carrier tube. This is a three piece part. The main tube is 3/8" and then slotted with an angle grinder. Then, with a couple of screwdrives, expanded to fit the inside of the main 1/2" tube (above). Then a chunk of the larger 1/2" tube is cut, slotted, and welded to the back (left) end as a stop so the tube won't slide through the big tube. Then another piece of 3/8" tuve is slotted, compressed, and slotted again. This piece fits inside the carrier tube and is welded in place. This piece is the inner stop for the cable sheath to bear against. The bare cable end comes out of the tube on the right side.|
|The main tube bracket is painted and bolted in. The cable is attached to the yoke (screwed in) with the rubber booty in place. You can see the original cable stop on the right side of the picture. The inner cable carrier (above) needed to be precisely fabricated to allow it to stop the cable exactly 2.75" (plus/minus 1/2" or so) further behind the original.|
|The inner cable carrier is fitted around the installed cable. Note how the cable end fits up into the cable stop. By pulling the carrier back (against the caliper mechanism), the carrier can be slid into the the main tube bracket. I figured I needed the inner carrier so I could rotate the slots to prevent the cable from popping out of the tube. With after thought, I realized it was unnecessary. But it was still a fun engineering exercise.|
|In this picture, the inner carrier is inserted into the main tube bracket. It is twisted 1/4 turn to drain any fluids that leak into it (mostly hydraulic I expect). The cable butt end is pulled out to help in installation.|
|Here you can see the entire installation, including how far the new tube sits back from the original. It's also higher than the original for a straighter cable pull. It's also a lot easier to install since I don't have to screw the cable in from within the tube - I can put the cable in the bracket after its end is screwed into the yoke. The fab work is not pretty, but works great. Now you can see why I didn't want my fabrication skills on public display.|