Hatachi 120 excavator air in fuel

Rebull1

New User
I have a hitachi 120 with 4 cyl motor it keeps getting air locked if you let it ideal other than a minute with the fuel half way open I replaced most of the copper washer grommets on the fuel connections and fuel lines still no luck . Once I bleed it at the filter it runs ok until l cut it off or let ideal for a little while. Any suggestions on where to look would be greatly appreciated.
 
Is this a EX120 or an FH120,big difference between the two engines,the EX has the Isuzu 4BDIT with an inline pump and the FH has an Iveco 8065T engine with a rotary pump.
AJ
 
Customer had one of these machine a few years back that was having the same problem. Never actually'found the problem'. Eventually though, after checking everything we could think of that might cause the problem, but we changed out the clear plastic tube that they used to bring fuel from the tank back to the engine.

Once we got the tube out, we pressurized it and looked for a leak, I even cut it from end to end to see if there was something stopping it up (even though it was clear and nothing was visible),and came up with nothing. Even though we found nothing wrong with the tube, once we changed it, he never had another problem with it.
 
As I said in the other post that there are two different engines fitted,in either case start at the fuel tank,wash the cap in fuel and blow it out as it doubles as a breather, (vent) then remove the supply line and see that there is a good flow coming from the tank,if not sort it,if it has a water separator clean it,if it's got the Isuzu engine it will have an in-line pump with a plunger type feed pump on the side of it,some of those had a glass bowl with a gauze filter inside,clean the bowl and filter,replace the fuel filter,fill the new filter with clean diesel before you fit it,open the bleeder on the filter and the pump,unscrew the plunger and prime it till you have air free fuel come from the filter,close that bleeder and continue on priming till the pump is air free,if that does not solve the problem it would be my guess that the feed pump has something trapped under one of its poppet valves,I have seen a piece of sewing thread under one of the poppet valves cause the problem you are having,you have probably solved the problem when you did not come back,if you have the Iveco engine I can advise on that also.
AJ
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top