Primary Brake shoe faces forward?
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Tuned
Joined: Sep 2010
Posts: 293
Likes: 1
From: South of Detroit
Primary Brake shoe faces forward?
Took off all 4 brake assemblies on my trailer. I'm quite sure the Primary shoe faces toward front of trailer. It's my understanding that the Primary shoe has less length of pad material on metal shoe than secondary. But as I move magnet on brake as if trailer is rolling forward, it seems like the front shoe moves out toward drum. It looks like braking in reverse the back shoe extends outward towards drum. Is this correct? Thanks. It just seems backwards to me.
Postmaster
Joined: Sep 2010
Posts: 3,472
Likes: 2
From: Southern Cal
Rick,
To Steve's point...
When the wheel cylinder at the top of the assembly, opens or expands to initiate braking, the front shoe starts to expand as braking starts. Due to wheel rotation, the front brake pad shifts the contact with the drum, through the adjuster on the bottom of the assembly, to the rear (larger) brake pad. This shift continues until the rear pad can't move any further, once hitting the pin located at the very top of the assembly, just above the wheel cylinder. Once this happens, the complete brake assembly continues to expand and braking occurs.
Since the majority of contact thru this process occurs on the rear drum, it's size is bigger to absorp this additional braking pressure.
Hope this helps explain the difference.
To Steve's point...
When the wheel cylinder at the top of the assembly, opens or expands to initiate braking, the front shoe starts to expand as braking starts. Due to wheel rotation, the front brake pad shifts the contact with the drum, through the adjuster on the bottom of the assembly, to the rear (larger) brake pad. This shift continues until the rear pad can't move any further, once hitting the pin located at the very top of the assembly, just above the wheel cylinder. Once this happens, the complete brake assembly continues to expand and braking occurs.
Since the majority of contact thru this process occurs on the rear drum, it's size is bigger to absorp this additional braking pressure.
Hope this helps explain the difference.
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