J284 backhoe hydraulic control valve leak |

This topic has 11 replies, 2 voices, and was last updated 10 years, 10 months ago by ronjin.

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- January 21, 2014 at 6:05 pm #30852
  edsmtn
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  The hydraulic control valve on my backhoe is leaking a lot of fluid but everything seems to be tight and can't easily see where it's leaking. It's not the hoses or their connections. Any suggestions?
- January 22, 2014 at 3:01 am #36689
  ronjin
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  Which backhoe do you have?
  
  ronjin
- January 22, 2014 at 12:24 pm #36692
  edsmtn
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  I have a 2004 Yangcheng hydraulic excavator – model jw03 4d1437 zl20
- January 22, 2014 at 9:53 pm #36698
  ronjin
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  If your JW03 is the same as mine shown in picture 1, you should be able to disassemble it as in picture 2 to determine the leakage point(s). Picture 3 is an exploded view.
  
  Is it leaking all of the time when the pump is running or only when you perform certain operations?
  
  ronjin
- January 22, 2014 at 10:38 pm #36699
  edsmtn
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  Thanks. Mine looks just like yours. I think it only leaks when I use it. Now that I have it exposed maybe I can pin down just when it is leaking. I think I'll wait till it warms up a little. I just about froze my buns off trying to get at it. The bottom is all wet with fluid but it's not obvious where it's coming from but it's nice and dry where the hoses are connected. I'll fire it up and see if I can see where it's leaking when it warms up a little.
- January 24, 2014 at 2:58 pm #36704
  edsmtn
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  On the bottom of the valve box there are six weep holes for the six valves. Two of the six are leaking fluid. Any suggestions? Thanks.
- January 24, 2014 at 3:36 pm #36706
  ronjin
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  Is it leaking whenever the pump is running and no controls operated?
  
  Or is it only when certain controls are activated? If so, is it though the whole run of the cylinder or only at fully extended or contracted?
  
  ronjin
- January 24, 2014 at 3:44 pm #36707
  ronjin
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  Here is a picture of one of the spools in the control block. I suspect that you need to replace the o-rings.
  
  ronjin
- January 24, 2014 at 6:07 pm #36709
  edsmtn
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  It leaks only when controls operated. Ron thank you very much for all your help. That picture really helps. The o-ring makes a lot of sense.
- January 24, 2014 at 6:43 pm #36710
  ronjin
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  Since it leaks only when controls are exercised, I am pretty certain that it is the o-rings.
  
  ronjin
- January 26, 2014 at 5:56 pm #36714
  edsmtn
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  Thanks again Ron. I was wondering where you got the picture of the spool. I had the first picture you sent from the paperwork I got with the tractor but that blowup of the spool was very interesting and wondered the source. Thanks again. Ed Shea
- January 26, 2014 at 7:28 pm #36715
  ronjin
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  My picture from several years ago when I had problems with one of my spools.
  
  ronjin
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