Results 1 to 8 of 8
  1. #1
    Platinum Member
    Join Date
    Jan 2008
    Posts
    823
    Location
    mountain valley near Tahoe
    Tractor
    Michigan 55A, Foton 254

    Default JW03 Hydraulic Backhoe-- slow when oil hot.

    Greetings, I have a JW03 on the Foton 254. When the oil gets hot, say after 15' of trench, the pull up igets slow. Is this common and to be expected?

    Thanks Richard

  2. #2
    Veteran Member Bob Rooks's Avatar
    Join Date
    Feb 2007
    Posts
    2,270
    Location
    Bothell & Silverdale, WA
    Tractor
    Yuchai Bulldozer

    Default Re: JW03 Hydraulic Backhoe-- slow when oil hot.

    This is not common nor expected.
    How hot does the oil get?
    Do the hoe hydraulics run off the tractor?
    Yuchai 306R dozer, Mustang 2040 skid steer, Mitsubishi MS035 Mini-Ex with four buckets and a rake, Trimble equipped 7' Dual Dozer with twin GCR-2 laser receivers, and a LiTW BH7600 back hoe (sold).

  3. #3
    Platinum Member
    Join Date
    Jan 2008
    Posts
    823
    Location
    mountain valley near Tahoe
    Tractor
    Michigan 55A, Foton 254

    Default Re: JW03 Hydraulic Backhoe-- slow when oil hot.

    Bob, The backhoe has it's own oil supply. I have no idea the temp of the oil. I dug a 50' trench for a friend yesterday, the last 15' there was less power.

  4. #4
    R.I.P.
    Join Date
    Dec 2008
    Posts
    5,883
    Location
    North Carolina
    Tractor
    Kubota BX2200

    Default Re: JW03 Hydraulic Backhoe-- slow when oil hot.

    Quote Originally Posted by valley View Post
    Bob, The backhoe has it's own oil supply. I have no idea the temp of the oil. I dug a 50' trench for a friend yesterday, the last 15' there was less power.
    It could be the relief valve is heating up a bit, and lowering the relief pressure.
    Or it could be that your unit is getting air into the oil.
    My unit returns the oil to tank very high, and that can lead to foaming. Someday, I will modify it to return the oil low (at least below oil level.)

  5. #5
    Elite Member RonMar's Avatar
    Join Date
    May 2005
    Posts
    2,760
    Location
    Port Angeles WA
    Tractor
    Jinma 284 delivered 06/28/05

    Default Re: JW03 Hydraulic Backhoe-- slow when oil hot.

    Quote Originally Posted by EE_Bota View Post
    It could be the relief valve is heating up a bit, and lowering the relief pressure.
    Or it could be that your unit is getting air into the oil.
    My unit returns the oil to tank very high, and that can lead to foaming. Someday, I will modify it to return the oil low (at least below oil level.)
    Yep, the HW-03 shoots the oil back thru a 1/4" ID hole right above the fluid level in the reservoir and it will entrain air in the oil being circulated over to the strainer. this air makes the pump make noise, especially when under load. When i fixed this, my pump immediatly started to run quieter, and has ever since.

    I agree, the relief could be a little different as the oil heats up. It could also be that it is bypassing a little around the boom lift piston seal when the fluid warms up. Where are you at(how hot is it outside) and what oil are you using in it? Next question is does the boom leakdown when left setting, and if so how fast?

    The next step is of curse adding a pressur gauge to measure exactly what pressure it is running at when it starts acting up. This is relatively easy to do on the HW-03 with the addition of an off the shelf metric to NPT hydraulic adapter which allows you to screw in a gauge right where the check valve is located. A gauge will be necessary to further isolate this issue and or adjust the relief valve if needed...
    Ron

  6. #6
    Platinum Member
    Join Date
    Jan 2008
    Posts
    823
    Location
    mountain valley near Tahoe
    Tractor
    Michigan 55A, Foton 254

    Default Re: JW03 Hydraulic Backhoe-- slow when oil hot.

    Greetings, Been busy, Just read your thoughts. The temperature is in the 90s here in Nevada. The oil I have in it is sold at Walmart. The pump is loud under load.
    We are working on a house to get it ready to rent. This will have to wait for a while, I'll come back to this and hope for your help when we get the house ready.

    Thanks Richard

  7. #7
    Super Member greg_g's Avatar
    Join Date
    Dec 2003
    Posts
    6,028
    Location
    Western Kentucky
    Tractor
    JD3720 Cab, 300X loader with 4-in-1 bucket

    Default Re: JW03 Hydraulic Backhoe-- slow when oil hot.

    Which model pump is supplying the HW-03? I ask, because one of the pumps on my KAMA (big brother to your TaiShan) would occasionally overheat. I was told that particular pump had its own internal relief valve, and that it was adjustable. But not all pumps have internal relief, hence my question about your model number.

    //greg//
    USN (Ret)
    Former Chinese tractor owner (x4)
    Current John Deere owner

  8. #8
    Elite Member RonMar's Avatar
    Join Date
    May 2005
    Posts
    2,760
    Location
    Port Angeles WA
    Tractor
    Jinma 284 delivered 06/28/05

    Default Re: JW03 Hydraulic Backhoe-- slow when oil hot.

    The pump on my HW-03 looks just like the main hydraulic pump on the Jinma. I don't think it has an internal relief, just a simple hydraulic pump. I would be curious exactly what that wallmart oil is, AW-32 or UTF?

    Richard, if you have access to a drillpress, you can slow down the velocity of the oil returning to the tank a bit by drilling out the center of the banjo bolt and opening up the cross holes that the oil returns to the tank thru. The oil passes from a nearly 1/2" hose down to a slightly less than 1/4" banjo bolt center. This jets the fluid back into the tank like a straight stream nozzle on a garden hose. Ever try to fill a bucket with a high velocity straight stream? You can never completely fill the bucket due to the air it entrains as it enters the bucket at high speed. Drilling out the banjo bolt and cross holes to as large as you can will slow the velocity that the oil returns to the reservoir. Slower speed = less air bubbles and less pump noise. I opted for an even larger opening, and I welded a 3/4" to 1/2" street elbow over the banjo bolt hole and replaced the entire return hose with a 5/8" hose that slips right over the smaller street elbow. This simple change immediatly quieted the pump.

    When you are ready to mess with it, give me a shout and i can show you exactly how I did this.
    Ron

Similar Threads

  1. Backhoe Pressure check on JW03 backhoe
    By Johnny P in forum Chinese Tractors
    Replies: 16
    Last Post: 06-03-2009, 06:41 PM
  2. Backhoe Hydraulic fittings on Jinma backhoe (jw03)
    By Amez in forum Chinese Tractors
    Replies: 9
    Last Post: 11-16-2007, 03:59 AM
  3. Backhoe JW03 BackHoe capacity??
    By DirtPoor in forum Chinese Tractors
    Replies: 15
    Last Post: 12-23-2005, 03:57 PM
  4. Hot Hydraulic Oil ?
    By GeorgeW in forum Kioti Owning/Operating
    Replies: 10
    Last Post: 06-19-2005, 12:46 PM
  5. Backhoe JW03 BackHoe side stabilization cyl Control ?
    By DirtPoor in forum Chinese Tractors
    Replies: 4
    Last Post: 10-08-2004, 03:58 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
© 2014 TractorByNet.com. TractorByNet is a registered trademark of IMC Digital Universe, Inc. Other trademarks on this page are the property of their respective owners.