Skid-Steer Spring-Applied Hydraulic Brake (SAHB) Pressure Switch


Skid-steers are an important part of the earth moving equipment line.  They complement the much larger bucket loaders and bulldozers.  They are smaller, more fuel efficient and maneuver very easily in tight spaces.  They are also very common on the rental market for they are easy to train inexperienced operators.  With that inexperience comes aggressive usage. 

Safety is always a top priority in designing off-highway equipment.  The design engineers develop systems that are not only rugged and strong but also as fail-safe as possible.  One of these systems that hydraulic engineers utilize is called a Spring-Applied Hydraulic Brake (SAHB) system.  This system always keeps the brakes on due to a large internal spring that is always in the “apply brakes” position.  When it is time to move the vehicle, the hydraulic pump loads the system with hydraulic fluid energy, pushes against the spring and releases the brakes allowing the vehicle to move.  This leads to a built-in safety feature:  if there is a hydraulic power failure, the brakes stay on and it will not freely roam.  




Application Challenge:  

Finding a rugged pressure switch that can withstand the rigors of being on a construction vehicle  

Being mounted on a construction vehicle, devices will be exposed to the extremes:  temperature, vibration, shock, abuse.   A pressure switch will also be exposed to large pressure spikes (someone hitting or slamming on the brakes)  long hours of operating and being exposed to heavy vibrations.  It is important that the pressure switch has a long life so down time is minimal and safety is not compromised.

Application Solution:

The PS61 Series Pressure Switch has undergone extensive testing in all aspects of  performing in a harsh construction environment:    

  • Tested for operating temperatures between -40°F to +250°F (-40°C to +121°C).  No matter where the vehicle is operating in the world, it will operate to specification and not poorly due to hot or cold temps.
  • MIL-STD-202G testing for shock and vibration during use on site.  Important that the pressure switch’s set point does not change.
  • Thermal shock testing (transitioning from hot to cold and vice versa very quickly).  For example:  a hot machine splashing thru a cold puddle of water
  • Tested to 2,000,000 cycles to ensure no parts break down and/or set points do not deteriorate. 
PS61 Series pressure

The PS61 Series pressure switch is your ideal solution for pressure detection in your Construction or OHV vehicles.  Its performance specifications will ensure you have a reliable switch with a long life to ensure your customers are kept happy!


Adjacent Products:

  • 3100/3200 : hydraulic pressure  
  • 1100 : Hydraulic pressure  
  • XM-700 : Continuous fluid levels
  • RFO : for Ag Sprayers
  • LS-700 : for Multi-Point Differential gear box oil measurement
  • Valve line : DG & BG series