1. Dustless Blasting Academy
  2. Adjusting and Calibrating

Re-tensioning the Abrasive Control Lever (VIDEO)

Is your abrasive lever too loose or too tight? Learn how to fix it here.

Identify the Issue

First things first, check to see if your abrasive control lever needs to be re-tensioned.

Too Loose

If you notice that the pinch valve assembly can still be rotated in the locked position, then it is too loose. This is due to the nuts and bolts that hold it in place vibrating loose over time. 

A loose rocker arm can prevent you from immobilizing the pinch valve assembly during transport, which can cause damage to the pinch valve air line, as well as the pinch valve assembly itself.

Too Tight

If it takes more than one arm to lock down the abrasive lever, then it is too tight.

A severely over tightened abrasive rocker arm can cause damage to the inlet nozzle, making it flared and resulting in inconsistent media flow. 

If you noticed either of the symptoms, then the rocker arm yoke needs to be adjusted.

Adjust the Rocker Arm Yoke

  1. Remove all (four) split pins from the rocker arm hinge yoke.
  2. Remove the two rocker arm connecting links, as well as the washers that go with them.
  3. Slide out the pedestal clevis pin.
  4. Now you’re able to remove the complete rocker arm assembly.
  5. To tighten the abrasive control lever: rotate the rocker arm hinge yoke one half turn clockwise.
  6. To loosen the abrasive control lever: rotate the rocker arm hinge yoke one half turn counter-clockwise.


  1. Refit the rocker arm assembly.
  2. Reinsert the pedestal clevis pin.
  3. Make sure that there is roughly a quarter inch of space between the base plate and the abrasive control lever.
  4. Reattach the connecting link plates
  5. Test the tension of the abrasive control lever to make sure that it locks firmly into place.
  6. Once a firm lock is achieved, insert the four split pins.

Does your blast pot look different?

If your blast pot was manufactured prior to 2020, you may have the old design. Click here to watch a video on how to adjust it.


Didn't solve your problem? Contact tech support here or call 713-869-2227.