otlski
Gold Member
Hope this helps. Are you low on fluid?
Backhoe JW-03 Backhoe Problems
- Thread starter cv63usafsfs
- Start date
Certainly should check fluid level, but don't believe I'm low.
I did run across this Parts Manual yesterday:
http://www.pegasus-industries.com/manuals/BackhoeParts.pdf
I did run across this Parts Manual yesterday:
http://www.pegasus-industries.com/manuals/BackhoeParts.pdf
little_fellow
New member
Hi everyone. I was looking for info on the JW03 backhoe and I stumbled onto this post. I am wondering how to check the pressure on the relief valve. I don't see a port where a gauge can be hooked up. Is this done by teeing into something.
This is a project I am working on. I took the Valve bank off the JW03 backhoe and took it all apart. I did find a few issues with it and now I am ready to reinstall it. Even though I did not play with the settings on the relief valve, I suspect it's been tampered with so I wonder how is the pressure checked on the relief valve and also, how much pressure should I have there?
This is a project I am working on. I took the Valve bank off the JW03 backhoe and took it all apart. I did find a few issues with it and now I am ready to reinstall it. Even though I did not play with the settings on the relief valve, I suspect it's been tampered with so I wonder how is the pressure checked on the relief valve and also, how much pressure should I have there?Attachments
RonMar
Elite Member
I machined a pressure gauge adapter that screwed into the check valve access plug on the top left of the valve body(has a large screwdriver slot on top) that allowed me to install a gauge there. I used an off the shelf 18MM to national pipe thread adapter and cut the shoulder back a little on a lathe to allow it to reach down into the hole far enough. I made a few for those who requested them and I believe I posted the dimensions in a thread here. Search this Chinese forum for "JW-03". I took a quick look and didn't find it... basically I machined the middle of the metric to NPT adapter to match the screw in plug contour with a shelf for the Oring, screwed it in where the plug was and screwed a gauge into that. Worked great...
RonMar
Elite Member
Ron Jindra was nice enough to send me these to repost as I lost track of them somewhere.
Here are the specs for making a gauge adapter and shows how/where it gets installed on the JW-03 control valve.
Good luck.
Here are the specs for making a gauge adapter and shows how/where it gets installed on the JW-03 control valve.
Good luck.
Attachments
little_fellow
New member
Thanks Ron. This information will be very useful. Would you happen to remember how many PSI would be preferable for this unit. I will be pressurizing it from a 7.2 GPM 540 RPM PTO Pump.
little_fellow
New member
I think that I found my answer in the PTO pump instruction manuel. It says here to set the relief valve at or below the rated pressure of 2,250 PSI.
erj
Gold Member
I have always been nervous about too much pressure, so I always set mine at 2,000psi and over the years it has been adequate.
RonMar
Elite Member
2250 Should be fine. In the dim recesses of my brain I seem to recall the Chinese manuals spec(in Bar) is actually a little higher than that, but you need to protect for the lowest rated component in the system. Often that component is the pump... Hydraulically the only real issue I had with mine was the return line into the tank. This is a low pressure line. They used a high pressure line thru a banjo fitting with about a 10MM bore. This sends the fluid back into the tank at high velocity. What mine was doing was this straight stream was shooting back across and into the top of the fluid level and pulling air down into the fluid right in front of the pump suction line. Shoot a straight stream from a garden hose nozzle into a bucket of water and you will see what I am talking about. Hydraulic pumps don't like air in the oil and will complain by making excessive noise(wine/squeal). I replaced the return line with a large diameter hose and a large bore hose barb into the tank when I installed a filter and the pump immediately went quiet...
At any rate 2250 is plenty enough force to break parts of the structure. You have a welder right? Pay close attention to the top of the bucket opening. I may have gotten a Friday bucket, but they put a piece of angle iron across the top of the opening for re-enforcement. Mine was basically held in place by about 3" of weld total across the entire width of the bucket and ends. It was a hard spot to weld and hard to inspect. This led to deformation and separation of the bucket sides from the back/top at the top corners. The top of the bucket opening is probably one of the highest stress areas on the BH when you curl and rip. All the stress from the teeth get transferred up the sides of the bucket to the corners of the opening then inward to the pivot. If the top/corner support(that crossbar) isn't adequate or welded properly to hold things square, the bucket will fail. Once damaged it was quite a bit of work to reshape and put in a proper piece of steel(3/8 X 2 X opening width) strap properly welded... If you can weld and fab, I would recommend this modification before you really use it hard as cutting out what is there and welding in the new stronger strap would be real easy and take about an hour on an un-damaged bucket...
At any rate 2250 is plenty enough force to break parts of the structure. You have a welder right? Pay close attention to the top of the bucket opening. I may have gotten a Friday bucket, but they put a piece of angle iron across the top of the opening for re-enforcement. Mine was basically held in place by about 3" of weld total across the entire width of the bucket and ends. It was a hard spot to weld and hard to inspect. This led to deformation and separation of the bucket sides from the back/top at the top corners. The top of the bucket opening is probably one of the highest stress areas on the BH when you curl and rip. All the stress from the teeth get transferred up the sides of the bucket to the corners of the opening then inward to the pivot. If the top/corner support(that crossbar) isn't adequate or welded properly to hold things square, the bucket will fail. Once damaged it was quite a bit of work to reshape and put in a proper piece of steel(3/8 X 2 X opening width) strap properly welded... If you can weld and fab, I would recommend this modification before you really use it hard as cutting out what is there and welding in the new stronger strap would be real easy and take about an hour on an un-damaged bucket...
little_fellow
New member
Thanks Ron. This is valuable info and I will definitely investigate this further.