Jump to content


brakes don't stop well when rolling backwards

  • Please log in to reply
21 replies to this topic

#21 DanielC


    Senior Member

  • Senior Member
  • PipPipPipPipPip
  • 4,745 posts
  • Location:West Linn,Or

Posted 27 December 2017 - 11:42 AM

Hydraulic pressure is equally applied to both shoes.  However, forward rotation wedges the shoes tighter to the drum.  When going backwards, the rotation tends to push the shoes away from the drum.  This effect is used on boat trailers with surge (drum) brakes that have a trailer brake master cylinder in the trailer coupler, so you can back the trailer even though reverse motion is applying the trailer brakes.  If a boat trailer has disk brakes, there has to be a solenoid to release hydraulic pressure back into the trailer master cylinder to back a disk brake boat trailer.

#22 distributorguy


    Senior Member

  • Senior Member
  • PipPipPipPip
  • 1,207 posts
  • Location:Metropolis, MN
  • Cars:77 Datsun 620, 73 Datsun 620

Posted 27 December 2017 - 02:23 PM

I store boats.  I cannot back up a boat/trailer with my tractor's 3-point using surge trailer brakes.  Period.  Unless I lock them out by preventing the tongue from applying them.