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too much noise

W

WV earth mover

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Mar 6, 2011
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WV
I bought a bank repo d4c hystat and only got to run it a few minutes befor bidding but now ive put about 20 hrs on it and cant get over the horrible hydrostatic noise i own another just like it that is completly diff noisewise . Nothing leaks ,nothing gets hot ,power is fine and there is no abnormal vibrations .I have a repair manual but it doesnt really discuss this issue i changed the hydro filters and fluid when purchased so today i had a someone else run it a while that has about 30 yrs exp on me he agreed there is definetly something wrong so does anyone have any suggestions on where to start checking. (its so loud if you look straight ahead you can barely hear the back up beeper)
 
L

Lee-online

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Jan 16, 2010
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Noises are hard to troubleshoot over the internet.

Does the noise stay the same. either in forward, reverse, steering, neutral etc.

Does the hyd overheat?

Can you remove the floor plate, rear cover at the motors and try to pinpoint it, either by feeling for vibration or using a broom stick on the ear.

PM me the serial number and i'll see what i can dig up on it.
 
W

WV earth mover

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Noise is not there when setting still even at full throttle starts being noticed when moving forward or reverse then gets 3 times louder when turning right or left whether forward or reverse or if going straight with the blade up its there but when you put a load on the blade its real bad even when you are going straight ahead .ive had the belly pan off to clean out and look for leaks but that was just after i bought it and before i discovered the noise and everything looked very good.
 
W

WV earth mover

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I sent you that ser# Lee-online but i'm a computer idiot so if you dont get it let me know and i'll try again.
 
W

WV earth mover

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It does track straight and has 5300 hrs but when your tracking straight at full speed blade up in forward or reverse on a slight downhill grade the noise rises and falls greatly almost like your having points of drifting and no load on the drive motors where my other one seems always have the same constent hydrostatic hum in this situation .
 
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W

WV earth mover

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Oil looks good but i dont know how old but it does have new filters . The thing that confusing me most is the fact that there is no one pump that is always under load so if i have a pump problem its both right and left pumps and if its a drive motor prob than its both cause the noise is there even when either one track is stopped . Ive spent the afternoon just simply reading the repair man and studying hydro flow schematics and since my lovely 500$ manual has no kind of troubleshooting in it i guess i might start with a good system fluid change then take the floor out and try to zero in like Lee online said ,the system isnt nearly as comp as i thought now that ive spent about 3 hrs reading about it so i guess i'll report back when i find out more in the meanwhile any advise will be greatly welcomed.
 
John C.

John C.

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High noise levels on hydraulic pumps is not uncommon. This machine is an older one so there may be plenty of internal wear. I would probably look for some kind of suction strainers to check for blockage as that will probably be the biggest reason for noise in pumps that are OK.

Good Luck!
 
W

WV earth mover

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I sent hydro oil samples in 2 weeks ago today , never done it before and dont know how long that takes . In the meantime i changed fluid and filters due to finding out fluid was about 6-8 years old and had around 4000 hrs on it, really made no diff but according to local cat service manager just changing filters and not fluid didnt make much diff on older powershift machines but is a big nono on hystats , he told me to look for line touching something it shouldnt in under the floor and transfering vibs up through the cab. How long does it normally take for oil sample results ?
 
xcmark

xcmark

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the test only takes about 45 mins , depends on the lab on how backed up they are. I have a local lab that does engine oil samples the same day if needed , they are located on a airport so they are more geared towards airplane anual oil samples, the last time I talked to them they where going to get more test equipment for other types of test.


http://advresearchctr.com/Home_Page.html
 
L

Lee-online

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After the lab gets the sample, they run all the samples first thing in the morning throughout the day. The following day they enter all the info into the system. So they take 2 full days.

Mailing them adds a alot of time. the post office takes a while to get them to the lab. It is best to drop them off at your local branch and it will get to the lab the next day.

If the serial number you pm'd me is correct, i have the report and can e-mail it to you.
 
M

maytag

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Mar 18, 2010
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124
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saraland al
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Hydraulic technician in a steel mill
noise

"Noises are hard to troubleshoot over the internet."

I like that, noise will sometime be the result of cavitation or an excessive amount of entrained air in the fluid. Excessive entrained air usually results in spongy, jerky movements with your cylinders/motors and no mention was made of this symptom.
Be interesting to see what the lab report says, BTW if you get a complete analysis for your fluid, particle, chemistry and water content you got a bargain-I pay $36 a sample for this with Exxon Mobil.

Tom
 
W

WV earth mover

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Iwent ahead and bit the bullet on the 95$ a bucket cat hydro oil . funny you mentioned air my local dealer asked me look for foamy air bubbles in the old oil at operating temp and it had alot dont know if that means oil was poor grade or just to old or what.
 
M

maytag

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saraland al
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Hydraulic technician in a steel mill
air

Typically in industrial hydraulics the fluid will contain 3-9% air. Its enough of a problem that your oil will have an "air release" number if you can pry the info from your supplier. Its been my experience that excessive air, to the point of being foamy
has always been a leak on the suction side of a pump or a return line or diffuser come apart in the tank-its very important that all lines be terminated below the surface of the oil-break the "surface tension" of your fluid and you introduce more air.

HTH,
Tom
 
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