truck carrying water tankers

Majority of truck owners out there know that the simple addition of an air suspension kit (or air bags, as they are more commonly known) can make a huge difference in the overall towing experience.

However, we receive a ton of calls from customers inquiring about controls for their air springs,. The standard manual fill valve, while cost effective;  isn’t the most convenient as it requires you to source a gas station for an air pump if you don’t already have an on-board air system on your truck.

We are often asked to recommend the best system for a user’s needs and the first question we always ask them is “do they want simultaneous or independent activation”. To which we usually hear “what’s the difference?”

It can be hard to decide between the air spring control options available on the market and to know which system to go with. So we are going to break down the available options, while looking at their pros and cons.

Single Path or Simultaneous Air Spring Activation system

Typically, there are two types of air spring inflation / activation systems – Single Path or Simultaneous Activation and Dual Path or Independent Activation. The system you end up choosing really depends on the type of loads your vehicle needs to carry.

Single Path or Simultaneous Air Spring Activation system is where inflation is achieved with one switch that inflates and deflates both air springs at the same time. As a result both air springs are inflated to exactly the same air spring pressure.

This system is particularly good for weights that are evenly distributed from side to side or front to back. It is not recommended for work trucks or slide-in campers but works extremely well for trailers.


  • Keeps both springs inflated exactly the same pressure – easy to keep an evenly distributed load level from side-to-side
  • Quick to inflate – only one valve
  • Simpler install, one less hose to route and one less hole to drill


  • Lose the ability to level loads that are uneven right-to-left
  • Can increase suspension movement (roll) during cornering, especially with a top-heavy load

Dual Path or Independent Air Spring Activation

The Dual Path or Independent Air Spring Activation system on the other hand, is where inflation is achieved with two separate switches, allowing for individual inflation and deflation of air springs.

This system is certainly best suited for vehicles with top-heavy or unevenly distributed weights.  Therefore, it is the best solution for work trucks and slide-in campers. Likewise, it may also work well for trailers with unevenly distributed loads.


  • Complete control to be able to level a load from side-to-side no matter how uneven the load is distributed right to left
  • Separates air springs to help control suspension movement (roll) during cornering, especially with a top-heavy load


  • Two hoses and inflation valves to install
  • Need to inflate each spring separately

In conclusion, Pacbrake recommends installing air lines in a dual path configuration. We believe the benefits outweigh the small amount of extra installation/inflation effort. However, single path is certainly a viable option if you don’t need to level your truck from side to side.

Pacbrake offers a variety of Air Spring Controls – choose between paddle valve or electrical operated kits available with digital or analog gauges.  

See Pacbrake’s Air Inflation Systems for more details.