Air Tank Not filling up to 150 PSI

If your air compressor is running constantly to fill the tank but isn't making any actual pressure, there are a few things that could cause this to occur.

  • Nasty Leak somewhere in the system
    • If one of THE fittings is allowing air to escape from the tank, you will start losing air as soon as it starts to fill. In turn, you may reach an equilibrium in which air enters the tank as fast as it exits the tank. This could be at 40, or 50 PSI.
      • You can diagnose this problem by spraying the tank/air lines with soapy water or Windex. Wherever a leak is present, the mixture will bubble up, even if the flow of air is very insignificant. Seal up any leaks in the system prior to testing again.
    • Check your solenoid valve(s) and make sure they aren't backward (if this is a new install). A backward valve will allow air to pass through it all the time and usually allows the tank to fill to 40 PSI before the tank doesn't fill any further.
      • The valves could be tested by removing a line/fitting from the outlet side. Check for airflow or spray down the connections for bubbles.
    • Make sure that your drain cock is closed all the way, as well as the blow-off valve. Both could be sprayed down to confirm.
  • Valve Issue
    • Check and ensure the valve is not stuck in the 'open' position.
      • Remove an air line (or fitting) from the outlet side of the valve. Is the valve allowing air to pass through constantly?
        • If the valve is allowing air to pass through, disconnect one of the two wires from it. Did that help? (Check your wiring if disconnecting it makes the leak stop).
      • If the valve will not stop flowing air, please see the warranty section below.
  • Compressor Issue
    • If you have already followed the steps above to seal the tank up and ensure there are no leaks, your compressor should start to fill the tank all the way without a problem. If the tank still won't fill past (x) PSI, the compressor may have some sort of internal issue. We can confirm this in a few different ways.
      • Allow the compressor to run and fill to the highest pressure it can. Once reached, remove the filter and check for back-flow. If the compressor is pushing air out of the filter housing in a steady stream, the unit is likely unable to build further pressure due to a bad seal of some sort.
        • A bad seal in the compressor usually requires a rebuild kit to repair. If your compressor is less than a year old, please see the warranty section below.
      • If you cannot build ANY pressure in the tank at all, start by unthreading the compressor from the tank. Hold your thumb over the end of the leader hose and let the compressor run. If the compressor cannot knock your thumb off the end of the hose, the unit is in need of repairs. If the compressor starts to knock your finger/thumb off, refer to the steps above.


For assistance starting the warranty process for your compressor, valve, or other components, please reach out to HornBlasters directly by phone @ (877)-209-8179, or by email to