valley
Platinum Member
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
Thanks Richard
JW03 Hydraulic Backhoe-- slow when oil hot.
- Thread starter valley
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Bob Rooks
Elite Member
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This is not common nor expected.
How hot does the oil get?
Do the hoe hydraulics run off the tractor?
How hot does the oil get?
Do the hoe hydraulics run off the tractor?
EE_Bota
Elite Member
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.)
RonMar
Elite Member
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...
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
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
greg_g
Super Member
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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//
//greg//
RonMar
Elite Member
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.
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.