A blockage in the mixing vessel of screed pumps will become evident when the pressure builds up on the pressure gauge and the screed pipe stops moving. Here are a few tips on how to locate and clear the blockage in the mixing vessel.

1. The easy way to locate the blockage is to walk upon the screed line. If the screed pipe is soft at the outlet of the vessel, we know it is a blockage in the mixing vessel.
2. Next, disengage the sending switch and release all the compressed air with the air relief valve.
3. Move on to switch the machine off and disengage the blades.
4. Disconnect the screed pipe at the outlet location.
5. Check the screed pipe for a blockage. If clear, it is obvious the blockage is in the outlet within the vessel.
6. Remove the safety grill to access the mixing vessel.
7. Dig away the screed to gain access down to the outlet from the inside. An obstruction may now be found. Use a narrow bar and place it in the outlet from the inside. Push the obstruction back into the cleared mixing vessel and remove.
8. Connect the safety grill back into place.
9. Reconnect the pipe and safety pin.
10. Switch the engine on, close the relief valve, engage the blades and switch the send button.
11. Monitor the pressure gauge to confirm delivery.