Hydraulic pump noise
Moark 05-18-2020
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Hey everyone. We've recently started hearing a noise  that sounds like it's coming from our hydraulic pump. It usually only makes this sound at certain rpms and when the volume control is adjusted higher it seems to increase the noise. We have a 2014 Concord 40meter with less than 600 hrs 

Have called Concord customer service and they have been very helpful in diagnostics but they are out of answers so I'm just curious if anybody has heard this before.

We've changed the pressure relief valve, all new filters, pressure is right at 350 bar, fluid temp is fine, accumulator holding pressure fine. 

gboom 06-01-2020
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what kind of noise do you hear? when it appears, is it a constant noise, and when you adjust the volume, does it go away? i suspect, that there is a bearing inside the pump, that is not 100% anymore, possibly unbalanced, and at certain rpms/settings the noise intensifies, to the point that you can hear it.

PUMBO 06-09-2020
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You have to isolate the noisy sound area first. The sound could be coming from from basically anywhere. Feel vibrations from hoses or locations from where the pulsating is occurring and work from there. Once you work out where the sound is coming from definitively fixing the problem is much easier than guessing. 

Moark 06-14-2020
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Thank you for your reply. The noise is basically a higher pitched whining noise. It only makes the sound when rpms are turned up. If we are pumping at lower rpms and we turn volume up, it will also make the noise. You are actually the second person to suggest a bearing going out. 

If it is a bearing, can the bearing can be replaced? I'm not familiar with these hydraulic pumps.

Thank you!

gboom 06-23-2020
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did you find out, what the problem is? yes, the bearings can be replaced, any reputable hyd. shop should be able to help you with that

Dipstick 06-17-2020
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Would like to hear is when you switch on the pump and preferably with some pressure so when you're actually pumping concrete. ;-)

TooTall 08-04-2020
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Try engaging the PTO in a gear Lower than normal. If it pumps in 7th gear, put the PTO in 6th gear. If the noise is the same, Exactly the same, it's likely not a bearing issue. If the noise is still present but at a noticeably Lower pitch, then it's possibly a bearing. 

Is the air pressure high enough in the hydraulic reservoir?