How to Free a Stuck Rotor on Your AST Spray Rig

In this video we will go over the steps to free a stuck rotor on your American Spray Technologies spray rig. Subscribe to our channel to see more videos! We are available by phone at 877-833-4342 or text at 253-833-4342. Visit our website: https://www.sprayrig.com Request a free catalog: https://goo.gl/7D5N3L Like AST on Facebook:   / sprayrig   Video Transcript: In this video, we will go over how to free a stuck rotor. If you notice that there is no slurry pumping out of the strainer assembly or if you are hearing a whining noise from the hydraulic relief valve when you turn your pump on, it’s a good indication that your rotor is stuck. You will also notice that when the pump is activated, the hydraulic pressure gauge is reading approximately 1800 PSI if you have a 150, 200, or 270 and 2100 PSI if you have a 350. Occasionally this will happen with a new spray rig, a newly installed stator tube, or if your machine has not been used for an extended period of time. First, try breaking the rotor free with the hydraulic motor. To do this, run your engine RPMs up to about 3400 RPMs for gas engines and 2600 RPMs for diesel engines. Next, adjust the pump flow control to 10 and turn the agitation flow control to the OFF position. Make sure your spray gun is pointing into the material tank with the ball valve open. If you have an electric switch on your spray gun, use that to turn the pump ON and OFF in 3 second intervals. If your equipment is controlled by an air switch or slide valve, then use the momentary switch on the air switch assembly, located on the side of the material tank, to turn the pump ON and OFF in 3 second intervals. The reason for using the momentary switch is because the slide valve has a slight delay, making the 3 second pause difficult to control. When the rotor breaks free, the hydraulic pressure will drop to 500-1000 PSI and you will no longer hear the whine of the relief valve. Quickly turn down the material flow control to 3 or 4 to slow the flow of mud. If this process is not working after multiple attempts, you can try breaking the rotor free manually. CAUTION: Turn off the engine, remove the key, and keep the key in a safe place while you do this, to ensure that the machine doesn’t accidently get started while you break the rotor free manually. The tools needed to complete this operation are a ¾” drive ratchet, a 5/8” 6-point socket that is ¾” drive, and an extension. We recommend using electrical tape to reinforce the connection between the socket and extension. Sometimes the sticky mud in the tube can create a vacuum effect and suck the socket off of the extension as you draw it back out. A few wraps of electrical tape can prevent this from happening. If you do not have an extension, you can use a pipe wrench to remove the pipe that houses the texture strainer to get closer access to the rotor. Unlock both camlock ears and slide the texture strainer out. At the end of the rotor, there is a 5/8” hex head. Seat the socket onto this hex head on the end of the rotor. You will know it is properly seated when the socket will not spin either way when rotated by hand. In this clip, we have removed the tube that houses the texture strainer so you have a better visual of the hex head on the end of the rotor. Attach the ratchet handle to the socket and extension and twist it counterclockwise to break the rotor free. This process works on both standard duty and heavy duty pump bodies on both trailer and skid units. Once the rotor is broken loose, reinstall the tube if you removed it, reinstall the strainer and hose by inserting the strainer back into the tube and closing the ears on the female camlock. At this point, you are ready to resume regular operation of your spray rig.