Hitachi UH122

[etd66ss]

I never said to rev. them up and I was talking in general not about electronic engines. My Hino was plugged in. It would spit and burp at very low RPM's sometimes up to about 30 seconds. The only way it would stay running was to wait until it would hit around 1000 RPM's and was running on all cylinders smoothly. It had a cloud of smoke so thick you couldn't see 5ft. 3 minutes later it cleared up and had no smoke at all. The engine was professionally rebuilt when I bought it and didn't use a drop of oil. Despite your thinking something is wrong with the engine that makes it a hard starter it is a known fact that some diesels are much harder to get going in the cold. Ih 282's and Standard Motors diesels in early MF 35 tractors are examples I know off. The Kubota in my skid steer is indirect injected and needs glow plugs on the 1st start if it 80 deg's. outside. Putting the throttle lever to full throttle makes a big difference when it's cold. Once it catches at I'd guess about 400 RPM I can move the throttle lever to idle. Same with the Perkins in my tractor. Only the Hino ever needed longer to reach a higher RPM where it stayed running. It doesn't mean there was something wrong with it.

My ford 1620 with 3 cyl shibaura is like that. Has to be set to 1000 RPM's to actually start, no matter the temp outside. Always have to use the glow plugs as well.

 

[361brock]

May I ask why the planetary cover is wet? Did you spill oil on it or is it weeping from the cover? On my UH143 it also has air tank with regulator like yours. If you pull up on the relief valve on top of hydraulic tank and release air pressure after you shut machine down, you will not lose as much oil from rotary manifold. Also pulling up on that relief valve anytime you blow a hydraulic hose will stem the flow of escaping oil.

Nick

 

[etd66ss]

May I ask why the planetary cover is wet? Did you spill oil on it or is it weeping from the cover? On my UH143 it also has air tank with regulator like yours. If you pull up on the relief valve on top of hydraulic tank and release air pressure after you shut machine down, you will not lose as much oil from rotary manifold. Also pulling up on that relief valve anytime you blow a hydraulic hose will stem the flow of escaping oil.

Nick

That is actually diesel fuel from a soaked rag I had sitting on the track above the planetary.

The air system is currently not building any air pressure as the previous owner really butchered the air system plumbing. (in fact if you watch the UH122-Start video, at the very end you can see the air tank is actually filling up with HYD oil). I'm not going to have time in the field to re-plumb the air system and get that working properly, just need to get the LH track from falling off the sprocket and/or idler so I can get this on a lowboy. The slack adjuster seal seems to be totally gone, can't build grease pressure and as soon as I track the LH drive backwards the track is all the way loose again.

My plan is to pump out the adjuster with the LH track in the air as far as I can get it and weld 3" x 3" x 1/2" THK x 2-1/2" LG angle tabs into the slot on the roller frame to keep the idler form moving back so far when tracking backwards. A temporary field fix to be able to manuever this to transport.

As I previously stated, it seems the previous owner had been running the machine with this butchered air system for some time, not sure what kind of condition the pumps are in, but I am going to have to run it as-is to get it transported then deal with the air system later. If the pumps are shot then they are shot, I don't have much time left to get this machine off the property.

 

[The Peej]

View this content on Instagram

View this content on Instagram

If this guy can get it done, you should have no problem. I’m sure your tracks are in better shape

 

[Tones]

@ etd66ss, excavators can be loaded onto a trailer with only 1 functional track if the rest of the machine is working properly by lifting 1 side and carrying it whilst driving the good side.

 

[skyking1]

I had mentioned that earlier. It helps if the trailer is in a straight line with the excavator to start with.

 

[etd66ss]

I went tonight and was able to lift the LH track off the ground and get the idler forward enough. Next time I go I will take a generator and my stick welder and get those pieces of angle welded into the slots on the roller frame, one each side, to keep the idler where it is.

The center joint dumps a decent amount of oil. I bet I will lose about 5 gallons loading this thing onto a lowboy. It dumps mostly when tracking. Both track motors work, but the LH seems a lot less powerful than the RH. I think that circuit is the one leaking so much oil.

Another issue is this hose for the RH track motor:



Not sure if I should replace this hose before calling out a lowboy and then having that hose pop...

I looked on the Daewoo and I might be able to scavenge a hose off that machine, it has the same 60 degree cone fittings.

 

[etd66ss]

I was able to get the idler keeper plated welded in today. Tested and works, can track backwards without the slack adjuster collapsing fully. Not great welds I know. I had trouble with the vertical welding. I don't stick weld that often:



The LH track barely has any power. I assume due to the fact the prev owner ran this machine without the air system plumbed properly, whatever pump drives that track is wiped out.

I got this hose out for the RH drive, need to make a new one as I don't trust this one for loading and unloading to transport:



Those BSPT threads were tight AF. Took a crows foot on an impact gun to break it free.

 

[Tones]

A few good smacks with a hammer before wrenching helps to loosen those nuts.

 

[Welder Dave]

The hose shop should be able to verify what thread they are. I doubt they are a British thread but could be wrong. I don't recall ever reading or hearing it's a pain to get hoses made for Hitachi's. On your vertical welds use a 6011 or 6010 and you can go downhill using a down and back up whipping technique. You're basically digging a groove and then going back and letting it fill up. Any other rods you want to go uphill. Make sure to use enough amps so you get decent penetration.

 

[etd66ss]

A few good smacks with a hammer before wrenching helps to loosen those nuts.

I did try that but the fitting is it a tough spot under the machine. The crows foot + 1/2 in drive impact worked really well.

 

[Acoals]

On your vertical welds use a 6011 or 6010 and you can go downhill using a down and back up whipping technique.

You saying to run with the rod pointing down? I don't know that I have ever tried that with 6010, I guess I will next time. Trying to go downhill with other rods never worked for me, but I am no master, especially out of position.

 

[skyking1]

The LH track barely has any power. I assume due to the fact the prev owner ran this machine without the air system plumbed properly, whatever pump drives that track is wiped out.

you can check that out with a hand or a heat gun.
If the drive motor is gone, it will pass a lot of oil and the return will heat up. Also note the temperature of the case drain from the drive motor.
If all the other functions seem normal then it is likely the drive motor and not a pump, as a faulty pump will affect some other functions.

 

[Welder Dave]

You saying to run with the rod pointing down? I don't know that I have ever tried that with 6010, I guess I will next time. Trying to go downhill with other rods never worked for me, but I am no master, especially out of position.

Rod is pointed up about 10 deg's to hold the puddle from falling but the progression is down hill. 6010/6011 don't get a thick slag covering and the slag isn't hard to burn through. Other rods downhill don't have much penetration and leave a concave bead. 6010 has good penetration and because the puddle freezes faster allows for more fill so you get a flatter or even convex bead.

 

[etd66ss]

The hose shop should be able to verify what thread they are. I doubt they are a British thread but could be wrong. I don't recall ever reading or hearing it's a pain to get hoses made for Hitachi's.

Pretty sure these are the fittings I need to make the hose:



I'll make the hose myself at work. I can get those fittings on eBay for a decent price.

 

[etd66ss]

you can check that out with a hand or a heat gun.
If the drive motor is gone, it will pass a lot of oil and the return will heat up. Also note the temperature of the case drain from the drive motor.
If all the other functions seem normal then it is likely the drive motor and not a pump, as a faulty pump will affect some other functions.

Well the other functions seem normal, however looking at the schematic both pumps seem to run the boom & stick:



When I lift the LH track off the ground it rotates just as fast as the RH. But under load it struggles.

 

[Tones]

The way the arm and boom hydraulics work is half the lever movement only one pump works, full lever movement engages both pumps. Once you get up and running properly you'll feel the difference in the levers.

 

[361brock]

My propel functions on Hitachi were weak when my rotary manifold was leaking. You might want to open the final drive plugs to check for hydraulic oil. If they are over full it would indicate track motor passing hydraulics into finals, another possible reason weak track motor.

Nick

 

[etd66ss]

My propel functions on Hitachi were weak when my rotary manifold was leaking. You might want to open the final drive plugs to check for hydraulic oil. If they are over full it would indicate track motor passing hydraulics into finals, another possible reason weak track motor.

Nick

The center joint is leaking terribly. I hope that's all it is and not a pump or motor. Just need to limp this thing on a lowboy for now. Can dig into all of its problems once I get it to my place.

 

[etd66ss]

Both machines are close to being fixed up well enough for hauling, still need to make one hose for each and then hope no more hoses pop: