Hitachi UH122

[Welder Dave]

That's why the loader bucket looked odd. It appears to be a side dump bucket. Pretty rare but not the most desirable. For the hose fittings just make doubly sure they are the right ones.

 

[skyking1]

yes it's a tipper. I've never seen a crawler with a tipper but Tucci had a few old JD 644b tippers.

 

[etd66ss]

yes it's a tipper. I've never seen a crawler with a tipper but Tucci had a few old JD 644b tippers.

I'd prefer a normal bucket, so much volume is taken away due to the side dump functionality.

 

[Welder Dave]

Find out the shape of the rest of the machine before worrying about the bucket.

 

[etd66ss]

I think I'm on the final stretch of field work for both machines. Made one new hose at work for the UH122 and ordered a hose assy online for the D65S-6, as it was cheaper for the assy than ordering just the fittings off eBay:

 

[skyking1]

hopefully the next pictures will have them on a lowboy.

 

[etd66ss]

I finally got the UH122 moved. The driver of the truck didn't like how janky the foot pedals were so he made me drive it on and off the lowboy. It was a bit of an adventure:






One problem I have with the machine is the fuel system doesn't hold prime. It will run for a couple minutes then die. Have to keep manually priming the system. Plenty of fuel in the tank.

 

[361brock]

Check your lift pump bolted to side of engine. It's a diaphragm type. You can install electric and do away with it. You will have to take it out of the loop or the electric pump might push fuel through the broken diaphragm into the engine oil.

Nick

 

[etd66ss]

Check your lift pump bolted to side of engine. It's a diaphragm type. You can install electric and do away with it. You will have to take it out of the loop or the electric pump might push fuel through the broken diaphragm into the engine oil.

Nick

I think I may have heard that vibrating one time when I shut the machine down. It's probably dry rotted etc.

 

[361brock]

Usually if the fuel tank is full you my not notice the problem. When the tank goes below half then it will crap out and you'll have the re-prime problem due to fuel starvation. Maybe the lift pump is still available. If you can't get your hands on a 24volt pump, just get a 12 volt one & hook to one battery, that's what I did.

Nick

 

[361brock]

You also might have a biological problem that is restricting fuel flow in lines or screen in tank. You might want to cut the fuel filter open and check for slime. If that machine has been sitting it's very likely your contaminated.

Nick

 

[Tones]

Those primer/lift pumps are repairable with rebuild kits available either Denso or Bosh. A darn sight cheaper and easier than fitting another pump. I have also seen rubber suction fuel lines delambimate internally which has all the same symptoms as you have.

 

[skyking1]

I don't see a puddle anywhere, looks like a smooth move.

 

[oarwhat]

Usually if the fuel tank is full you my not notice the problem. When the tank goes below half then it will crap out and you'll have the re-prime problem due to fuel starvation. Maybe the lift pump is still available. If you can't get your hands on a 24volt pump, just get a 12 volt one & hook to one battery, that's what I did.

Nick

In my experience hooking up to one battery will greatly reduce the life of your batteries. When charging the batteries the one with the draw on it will not charge properly.

 

[361brock]

That little electric fuel pump won't have much effect on the battery, I had it connected like that for 10 years, never noticed anything. Those group 31 batteries won't even know it's there.

Nick

 

[etd66ss]

I ordered a pdf parts manual online last night and I don't see anything about a diaphragm pump on the engine. I think this machine is supposed to use the air tank to pressurize the fuel tank just like the hydraulic tank?



I don't really understand what is going on with items 10-19, my machine has nothing like that anywhere.

 

[Tones]

Can you post a photo of the fuel injection pump. All the photos I've seen of these engines shows a lift pump mounted on the injection pump which was typical of most Japanese engines of this era including Hino, Komatsu and Isuzu.

 

[361brock]

Yep, lift pump on my 1985 hitachi UH143 with Hino was mounted to block just under the main injection pump. Easy to change provided thats the issue.

Nick

 

[etd66ss]

Can you post a photo of the fuel injection pump. All the photos I've seen of these engines shows a lift pump mounted on the injection pump which was typical of most Japanese engines of this era including Hino, Komatsu and Isuzu.

I'll get a pic of the engine soon, but from the parts manual the only pump connected to the injector is the hand primer that pumps fuel into the filter housing:



This is the canister I sometimes hear vibrating after I shut down the engine:

 

[Tones]

If what you are calling a canister has the dome nut on the top is a centrifugal oil cleaner and should be cleaned out at every service. The gunk inside has to be scrapped off.
Back to the lift pump, what you have circled is indeed the primer but it's also the lift pump and driven off the injector pump so it's a combination of both. On the inlet side is the famous or infamous screen in the banjo bolt which is also worth checking at this time. In the lift pump there's 2 nylon plungers that get pitted causing a loss of suction. European engines use this same set up. I've put a Denso kit into a Scania truck engine with a Bosh fuel system so I know they'll go the other way. A kit would cost about 20 bucks and about 1|2 an hour of your time.

PS the plunger has to be screwed down when not in use, leaving it lose will cause it to wear out.