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Loud clanking sound from the hydraulic service manifold (HSM) accumulators


A loud clanking sound from one of the hydraulic service manifold (HSM) accumulators can be heard while the actuator is being cycled, accompanied by around a 100psi pressure pulse on the HSM pressure output gauge with each cycle of the actuator piston (Video 1).


Video 1 – Example of loud noise and pressure pulse from a 293.32 HSM pilot pressure accumulator (Click on to open link)




First, with hydraulic pressure off, confirm the pre-charge on each of the accumulators on the HSM.  If any of the pre-charge pressures is low it will need to be pre-charged again. 

If pre-charge pressures are correct, run the system for 5 to 10 minutes. Carefully touch the top section then the bottom section on the cylinder of each accumulator on the HSM. 

If one of them is hot in this section it could indicate the oil made its way over to the gas side and the system pressure can only compress the gas side a little bit.  If that is the case the accumulator may need to be replaced.  



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