Henry stlouis
New Member
Whining/hissing noise coming from near hydro filter. Thinking maybe pump is cavitation not sure how to fix. Machine also try’s to swing a little when first started.
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Cat 304 hydraulic whining noise
- Thread starter Henry stlouis
- Start date
Nige
Senior Member
Try posting a Serial Number.
When was the last time the hydraulic oil & filters were changed and all the screens removed, inspected, & cleaned.?
If you say the machine tries to swing when you hear the noise it could be a partly stuck spool in the control valve that is not centering correctly.
When was the last time the hydraulic oil & filters were changed and all the screens removed, inspected, & cleaned.?
If you say the machine tries to swing when you hear the noise it could be a partly stuck spool in the control valve that is not centering correctly.
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funwithfuel
Senior Member
Is it freezing where you're located? I'm guessing you might have contaminated oil. I would try and take a sample off the bottom when cold. Then again when warm. Let the samples set overnight. See if water doesn't drop out to the bottom.
Henry stlouis
New Member
It is a machine a just purchased. Hydro fluid as well as filters were just changed. It has not gotten below freezing yet. CAT0304EVME402384
funwithfuel
Senior Member
Was the proper oil used at service? Maybe take a look at the return filter and pay close attention to the bypass. They will sometimes fail at the bend where it is formed. Also be mindful of your pressure cap/valve. If you're not maintaining positive pressure, the pump will pull air. Check the suction pipe to the pump and the flexible joint between the pipes. Make sure all clamps are tight, no evidence of seepage.
Nige
Senior Member
What type & grade of hydraulic oil did you put in it.?
Did you remove and clean the suction strainer/screen from the bottom of the hydraulic tank while it was drained.?
Most important since you just acquired it. Is the Operation & Maintenance Guide in the pocket behind the seat.? If not you need to get hold of one soonest. Cat Publication is SEBU9418 and can be downloaded for $75 from - https://catpublications.com/
EDIT: By any chance did the noise start after the oil was changed.?
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Nige
Senior Member
If you want a CD at a discounted price try here - https://www.ebay.com/itm/313350896042
These are genuine Cat manuals BTW.
These are genuine Cat manuals BTW.