The pump truck suddenly does not pump for the following reasons:

Aging of pump truck:

Aging of the pump truck, including excessive wear of the S-valve, the discharge pressure does not meet the design standard, resulting in insufficient accumulator pressure, or insufficient engine power.

Pump pipe cleaning is not thorough:

Pump pipe cleaning is not thorough, there are solidified old concrete in the pipe, resulting in increased resistance of pump pipe.

Unlubricated pump pipe:

The pump pipe is not lubricated with water or mortar at the new opening, resulting in increased resistance

Pipeline material problem:

Pipe passing long, too much bending, if it is to drag the pump, it may be that the discharge height is too large to cause the pump car to not pump.