10-09-2012, 05:49 PM
Brad/Gordon,
Here's my pennies worth.....
So far I have not been in a situation where I applied maximum braking effort. I would be very unhappy if my tag wheels locked up and flat spotted. My ABS may prevent that, but as Gordon suggests you also need to be applying an appropriate braking force to the wheels. We have all seen the lightly loaded wheels on an empty flatbed lock up when the 18 wheeler is just trying to stop for a light or slowing traffic.
I have attached a little blurb on brake chambers. I think you will find that the numbers Gordon mentions represent the number of square inches of diaphragm surface. As you know the force produced is proportional to the air pressure applied and the area of the diaphragm. I really don't think the length of the shaft has any bearing on the force unless it is extended to its maximum length and then the force stops at that point. That is why the point where you adjust the brakes is based on the extension and length of the rod when the brakes are applied. In a modern air brake system, the self-adjusters take care of that until it is time for new shoes/pads. So, as Gordon suggests, should the wrong chambers have somehow been installed, braking forces on the tag could be excessive and result in lockup.
Here's my pennies worth.....
So far I have not been in a situation where I applied maximum braking effort. I would be very unhappy if my tag wheels locked up and flat spotted. My ABS may prevent that, but as Gordon suggests you also need to be applying an appropriate braking force to the wheels. We have all seen the lightly loaded wheels on an empty flatbed lock up when the 18 wheeler is just trying to stop for a light or slowing traffic.
I have attached a little blurb on brake chambers. I think you will find that the numbers Gordon mentions represent the number of square inches of diaphragm surface. As you know the force produced is proportional to the air pressure applied and the area of the diaphragm. I really don't think the length of the shaft has any bearing on the force unless it is extended to its maximum length and then the force stops at that point. That is why the point where you adjust the brakes is based on the extension and length of the rod when the brakes are applied. In a modern air brake system, the self-adjusters take care of that until it is time for new shoes/pads. So, as Gordon suggests, should the wrong chambers have somehow been installed, braking forces on the tag could be excessive and result in lockup.
Russ White
2016 Winnebago Vista LX 30T
#530 ( Sold )
1999 45' Double Slide - Factory upgrade 2004