Hitachi UH122

[Timneh1952]

I have the uh123

 

[Tones]

In regards to the Isuzu engines models, the core of the engine would have to be the same with the difference between industrial and truck being the fuel system. IMHO pistons, rings, bearings, valves and seal kits etc would be the same. Thepumpguy should be able to enlighten you about the fuel system as to whether it's rebuildable or replaceable off the serial numbers on what you have.
You should be thankful youre not trying to restore a UH12 with a Hitachi engine, parts for those are like rockinghorse shyt.

 

[361brock]

I have a UH143/UH12 and it has the Hino engine. Was made for the euro market in 1985. I had it sent to New Jersey then to Staten Island. Was brand new, grey market, not available in USA at the time. Mine came from Holland, German writing on interior warnings. That Hino is one of the best running engines I ever owned, and so quiet.

Nick

 

[Welder Dave]

I had a Hino truck. Very cold blooded but incredible fuel economy. 14 or 15 mpg on a 4 ton dump truck.

 

[Timneh1952]

Yes my hino is so quiet the uh123 is a back up great demo excavator a beast hard too find one I'm glad I purchased it

 

[etd66ss]

I almost have all the parts/service/operators manuals I need. Mostly found downloadable pdf's, but had to buy a few paper copies from eBay.

Unlike my brothers' Koehring 6608, it seems I can find UH122 main pump parts from places like FridayParrts in China: KVC925

Hopefully I don't need any engine or pump parts, just seal kits...

 

[Timneh1952]

Good glad you found them.yup china

 

[etd66ss]

One manual I cannot find online and that is for the hydraulic components parts lists.

I can find one for a UH10-2/UH121: UH10-2/UH121
I can also find one for a UH10-7/UH123: UH10-7/UH123

However I cannot find any for UH122 specifically. Were there any UH10 dash numbers between a -2 and a -7 that is the equivalent to a UH122? It seems like my machine is between those.

I'm tempted to just grab both of these manuals and hope they cover any part numbers I'd need to search for.

 

[etd66ss]

Double post

 

[Diesel Dave]

What’s the part number listed in your book for one of the complete main hydraulic pumps ?

 

[etd66ss]

What’s the part number listed in your book for one of the complete main hydraulic pumps ?

4100781 PUMP; PLUNGER

 

[Diesel Dave]

Key 23A part # 4089122 is broken down at AVspares.
https://avspare.com/catalog/hitachi/156:uh123/ab1fb6de-aa09-4b12-a6f9-3a726a51ccaf/ .

 

[etd66ss]

Key 23A part # 4089122 is broken down at AVspares.
https://avspare.com/catalog/hitachi/156:uh123/ab1fb6de-aa09-4b12-a6f9-3a726a51ccaf/ .

I guess I am a bit confused by the item numbers on the diagram. Item 23 the QTY is 2, while item 23A the QTY is 1 (machine has 2 variable displacement pumps, seems like QTY for item 23A should be 2). Is that saying the 4089122 pump is a replacement for the 4100781 pump? Then item 23B is not even a pump but some kind of internal valve?

Also on AVSpares under compatible equipment models for the 4089122 pump it lists UH121, UH123, UH171 & UH081, but not UH122.

Thanks for finding on AVSpares, I have used that site in the past to find part numbers.

I think what I will do is buy both the hydraulic equipment manuals for the UH121 & UH123 and hope for the best when I get into the UH122 pumps & valves for inspection if/when I get going on this machine.

Seems like the UH122 is an odd duckling for some reason...

 

[Diesel Dave]

Key 23 part # 4100781 is the number for the complete pump.
Key 23A Part # 4089122 is the number for the pump without the regulator.
Key 23B Part # 4100781 is the pump regulator.

 

[etd66ss]

Key 23 part # 4100781 is the number for the complete pump.
Key 23A Part # 4089122 is the number for the pump without the regulator.
Key 23B Part # 4100781 is the pump regulator.

Ah, I get it now, thanks!

 

[Diesel Dave]

 

[etd66ss]

Yeah, it's just when I click on any of those pages, the diagrams have a UH123 watermark at the bottom left corner.




And my plan to buy the UH121 (P1719-H-5-1) and the UH123 (P156-E1-1) equipment parts manuals didn't really pan out, both pump setups look very different than the UH122:





But in the UH123 manual I downloaded (156-E1-1) only shows a single pump that looks fixed displacement?

I will use AVSpares for now, but I'd really like to find the P1719-H-6 manual someday.

 

[etd66ss]

 

[etd66ss]

The dual pump setup for the UH123 is in a horizontal arrangement like the UH121:
https://avspare.com/catalog/hitachi/156:uh123/eda1268c-33fe-4238-9dfc-965de33ff76f/

I guess I'll deal with all this when the time comes to find seals. Was just hoping to get all the manuals ahead of time.

 

[Diesel Dave]

UH122 is an odd duck for sure.
I saw your pic of the Staffa type swing motor, bet that will have some torque !