piper184
Platinum Member
IT is the top file on that page called "Jinma 200 Series Documentation". That file has a lot of information that was not in the actual Jinma manuals.
Backhoe Jinma JW-03 backhoe manual desperately needed ASAP
- Thread starter DickJuneau
- Start date
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piper184
Platinum Member
That is a pretty decent video although the equipment is newer than ours.
You should have a screen inside the hydraulic tank on the suction line end. If you don't have fluid in the tank yet just take of the flange with 3 bolts and check the screen. It is not as good as a filter, which can be added on and may be standard on later years.
A couple of things I did to make it easier. First I welded the nuts onto the brackets that hang from the 3point pins. Then all i have to do is take an impact wrench to it once the bolts are started.
I also made a bracket to connect to the top link bracket. This was suggested in the Documentation that I referred you to earlier. It makes it a little more difficult when connecting the backhoe but I think the added strength is well worth it.
Another thing I did was have custom adapters made for the pump so I could put quick couplers on the hoses. Saves a lot of mess as you can see by the video.
Following an old suggestion from somewhere, I run the transmission "over full". This causes a big mess when mounting the pump. My solution is to back the rear wheels up onto the trailer and mount the pump before heading for the backhoe. Works like a charm.
I also made a rolling cart to hold the backhoe while it is off of the tractor. That allows me to easily move the backhoe from the carport to the garage and do the mount/unmount on a nice concrete floor.
One more thing, if you fill the backhoe tank to the bar in the filler neck when it warms up the fluid will expand and rise to the bottom of the filler tube. That will cut off the air vent in the filler cap and cause the tank to spit fluid all over everything! The bottom of the filler neck is lower than the top of the tank. At least it is on mine. To fix this I drilled out the dipstick tube fitting and put a vent hole in it. That way I can have more fluid in the tank to aid heat dissipation on hot days.
Hope this helps
You should have a screen inside the hydraulic tank on the suction line end. If you don't have fluid in the tank yet just take of the flange with 3 bolts and check the screen. It is not as good as a filter, which can be added on and may be standard on later years.
A couple of things I did to make it easier. First I welded the nuts onto the brackets that hang from the 3point pins. Then all i have to do is take an impact wrench to it once the bolts are started.
I also made a bracket to connect to the top link bracket. This was suggested in the Documentation that I referred you to earlier. It makes it a little more difficult when connecting the backhoe but I think the added strength is well worth it.
Another thing I did was have custom adapters made for the pump so I could put quick couplers on the hoses. Saves a lot of mess as you can see by the video.
Following an old suggestion from somewhere, I run the transmission "over full". This causes a big mess when mounting the pump. My solution is to back the rear wheels up onto the trailer and mount the pump before heading for the backhoe. Works like a charm.
I also made a rolling cart to hold the backhoe while it is off of the tractor. That allows me to easily move the backhoe from the carport to the garage and do the mount/unmount on a nice concrete floor.
One more thing, if you fill the backhoe tank to the bar in the filler neck when it warms up the fluid will expand and rise to the bottom of the filler tube. That will cut off the air vent in the filler cap and cause the tank to spit fluid all over everything! The bottom of the filler neck is lower than the top of the tank. At least it is on mine. To fix this I drilled out the dipstick tube fitting and put a vent hole in it. That way I can have more fluid in the tank to aid heat dissipation on hot days.
Hope this helps
RonMar
Elite Member
That filter is on the return line from the sump to the pump and It is probably(should be) a strainer and not a filter as filters on the suction side can cause issues by restricting flow. My JW-03 did not have a filter, it did have a strainer(#100 mesh) on the pump suction line inside the tank. I added a 10 micron filter, but you want to push fluid thru those so I placed that filter on the return line coming out of the control valve and back to the tank. I had to do one other small modification also as they used a restrictive banjo bolt where the return line connects to the tank. This line should have no restriction or back pressure on it but that fitting caused enough back pressure at full flow to blow the seal out of my filter assembly till I replaced the fitting and line with a plain elbow and hose barb. been working fine for years now.
TIPS:
1800 RPM is a real good spot. it uses single acting boom swing cylinders(low volume) so any more flow gives a real twitchy boom swing
If you have ever run a backhoe before forget what you have learned. The JW-03 valve does not have individual load check valves, so multiple functions can be confusing when a heavier loaded cylinder actually goes the opposite direction than commanded. IE: Boom up and dipper up at the same time will result in boom down and dipper up. boom up pretty much has to be done by itself unless you have the dipper and bucket loaded/engaged like when ripping. So any backhoe memory you might have will have to be unlearned
Look closely at the top of the bucket opening. This is probably the highest stressed point on the backhoe. Mine was horribly re-enforced and not welded on the inside at all and failed rather quickly. Luckily I caught it right when it cracked so it was fixed easily. I replaced the top inside metal with a strip of 2" X 1/2" bar stock welded both sides and added triangular gussets between the bucket brackets and the top edge of the bucket. I can put up video of what I did to it if you are interested.
TIPS:
1800 RPM is a real good spot. it uses single acting boom swing cylinders(low volume) so any more flow gives a real twitchy boom swing
If you have ever run a backhoe before forget what you have learned. The JW-03 valve does not have individual load check valves, so multiple functions can be confusing when a heavier loaded cylinder actually goes the opposite direction than commanded. IE: Boom up and dipper up at the same time will result in boom down and dipper up. boom up pretty much has to be done by itself unless you have the dipper and bucket loaded/engaged like when ripping. So any backhoe memory you might have will have to be unlearned
Look closely at the top of the bucket opening. This is probably the highest stressed point on the backhoe. Mine was horribly re-enforced and not welded on the inside at all and failed rather quickly. Luckily I caught it right when it cracked so it was fixed easily. I replaced the top inside metal with a strip of 2" X 1/2" bar stock welded both sides and added triangular gussets between the bucket brackets and the top edge of the bucket. I can put up video of what I did to it if you are interested.
Bob Rooks
Elite Member
OP
DickJuneau
New member
Thanks for the VERY timely reply! I was heading to our hydraulics shop to get the filter installed when I read your great post. I was able to get rid of the banjo fitting as you advised. Thanks very much for all of this info, Ron, and I'd love to see a video of how you reinforced the bucket.
OP
DickJuneau
New member
Ok, I got everything hooked up for the Jinma JW-03 backhoe. I put 5 gallons of hydraulic oil in the tank. At this point I'm confused about which levers have to be engaged for the backhoe to work. What is the sequence for getting the backhoe ready to operate? The manuals are quite confusing for someone who has never operated the tractor before. It's a forest of levers to an old man's eyes, ha ha. Thanks.
piper184
Platinum Member
If the pump is mounted and plumbed properly, you have to turn on the PTO. There should be two levers to do that. One by your right foot, Step on the clutch, all the way down and push down on that lever. You may get a little gear grinding so make sure the tractor is at idle and hold the clutch all the way down for a few seconds. Push the lever down quickly to keep the grinding to a minimum. You may need to adjust the clutch, but that is another subject entirely.
The second PTO lever is near the back of the tractor and should be marked 540 and 1000. It has 3 detent positions. 540 - N - 1000. This lever only controls the speed of the PTO shaft itself and has no effect on the PTO driven pump for the backhoe. Just put this lever in the center (N) position to keep the PTO shaft from turning.
Once you have the PTO engaged and the pump running the hydraulics will be live on the backhoe. On mine the levers were plumbed differently than every other backhoe I had ever run, so I swapped a couple of the hoses around at the valve body. The labels are now wrong, but it works the way I like it to.
just move one lever at a time until you figure out which lever does what. I will look tomorrow and see if I can find any diagrams that describe the functions of the levers.
The second PTO lever is near the back of the tractor and should be marked 540 and 1000. It has 3 detent positions. 540 - N - 1000. This lever only controls the speed of the PTO shaft itself and has no effect on the PTO driven pump for the backhoe. Just put this lever in the center (N) position to keep the PTO shaft from turning.
Once you have the PTO engaged and the pump running the hydraulics will be live on the backhoe. On mine the levers were plumbed differently than every other backhoe I had ever run, so I swapped a couple of the hoses around at the valve body. The labels are now wrong, but it works the way I like it to.
just move one lever at a time until you figure out which lever does what. I will look tomorrow and see if I can find any diagrams that describe the functions of the levers.
Bob Rooks
Elite Member
According to his picture he's using the upper tang drive live PTO, which turns all the time at engine speed. Or am I missing something?
piper184
Platinum Member
You are correct. The lever in this picture turns on the PTO system. Push down to EN-gage. This must be engaged in order for the internal tang shaft to be used.
The lever at the back is a speed selector for the 6 spline PTO shaft. It has a neutral position so that you can stop the PTO shaft from turning while still powering the internal lug at engine speed. This is handy for safety if you don't have the screw on cover for the shaft.
RonMar
Elite Member
Here you go. Jw/hw-03 backhoe bucket mods - YouTube
Getting rid of the banjo also gets rid of another issue. It caused the return fluid on mine to return in a high velocity straight stream which entrained a lot of air(shoot a straight stream from a garden hose into a bucket to see what I mean). These air bubbles would flow down past the pump supply port and get sucked in, causing the pump to make noise. Once I got rid of it, the pump got real quiet...