Backhoe Dual circuit brakes: What am I misunderstanding

   / Dual circuit brakes: What am I misunderstanding #1  

Tony H

Platinum Member
Joined
Mar 18, 2013
Messages
622
Location
Summit, NY
Tractor
JCB MIDI CX
My backhoe has dual circuit brakes. I lift the rod between the two brake pedals so you can Brake one side or the other.
I thought I should be able to drive backwards, with the bucket lifting the front wheels off the ground, and steer the tractor by using one brake peddle or the other.
Snow plowing. I thought I should be able to use one brake peddle to the other to aid in steering as the weight of the snow wants to push the front of the tractor.
 
   / Dual circuit brakes: What am I misunderstanding #2  
The split rear brakes are meant to enhance the turn, but you still have to steer the front wheels! There's no way bringing one rear wheel to a halt is going to make the front end of the tractor turn very much all on its own... there's just way too much weight on those front wheels (or the bucket, if you've jacked the wheels off the ground that way).

Farmers use the split brakes to make a sharper right angle or 180 degree turn at the end of a row when doing field work, but it always works together with fully steering the front wheels.
 
   / Dual circuit brakes: What am I misunderstanding
  • Thread Starter
#3  
The split rear brakes are meant to enhance the turn, but you still have to steer the front wheels! There's no way bringing one rear wheel to a halt is going to make the front end of the tractor turn very much all on its own... there's just way too much weight on those front wheels (or the bucket, if you've jacked the wheels off the ground that way).

Farmers use the split brakes to make a sharper right angle or 180 degree turn at the end of a row when doing field work, but it always works together with fully steering the front wheels.

Thank you. I really thought it should be able to steer the tractor as you back-blade with lots of down pressure on the bucket. I'll play a bit more now that I know what should work.
 
   / Dual circuit brakes: What am I misunderstanding #4  
Split brakes are a hold-over from the days when farm tractors were 2wd only and had most of the weight on the back tires (typically 65-75%). With comparatively little weight up front, locking up one rear tire would enable those old tractors to virtually pivot on the locked wheel - a turning radius of zero, which was pretty handy for field work.

Modern equipment with 4wd and a loader has a very different weight distribution... they can even be front-heavy unless there is weight added to the back to counterbalance the weight of the loader on the front. As a result, use of the split brakes for turning is less common. The split brakes do have value as a means of transferring power to the wheel with more traction when the tractor is stuck, although the locking differential on many tractors does the same thing.

Suggest you keep the bottom of the bucket flat to the surface when back-blading with heavy down pressure. If you have the edge digging into the surface, anything you snag can send extreme shock loads to the loader's hydraulic cylinders and pins, with the potential for damage to same. Back blading with the edge should be limited to loose material that should not need down pressure.
 
   / Dual circuit brakes: What am I misunderstanding #5  
Yes, farm tractors of yesteryear could turn on a dime with the use of the "turning brakes," especially when equipped with a "narrow front end" (a single front wheel or a pair of "duals").

But the split brakes remain essential on modern tractors for some applications. I can't turn toward the uphill side when mowing with my 4wd tractor worth a darn without using them. Nor make sharp turns at the corners.
 
   / Dual circuit brakes: What am I misunderstanding #6  
My backhoe has dual circuit brakes. I lift the rod between the two brake pedals so you can Brake one side or the other.
I thought I should be able to drive backwards, with the bucket lifting the front wheels off the ground, and steer the tractor by using one brake peddle or the other.
Snow plowing. I thought I should be able to use one brake peddle to the other to aid in steering as the weight of the snow wants to push the front of the tractor.

You are correct. I once picked up a big block of concrete with my backhoe - tipped my tractor over backwards. I ended up riding the resulting wheelie for a quarter mile, steering entirely with the brakes, to the spot I was dumping the concrete. Are you having problems? There might be too much force generated with your snowplow scenario to overcome the deflection with brakes, but I would think you could do it.
 
   / Dual circuit brakes: What am I misunderstanding #7  
The unbraked tire may not be getting the traction you need in the snow to achieve the desired result or the braked tire may be sliding along.

What happens when you try to brake steer in the scenario you describe?
 
 
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