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Hitachi EX100-2 hydraulic problems

Kutter's

Member
Hey guys, I was looking for some help on this ex100. or ideas where to start. so, everything works fine besides the bucket curl out. it gets really jerky and sometimes will kill the machine if you stay with it. it tracks good stick works good boom, and bucket curl in
 

mg2361

Senior Member
Welcome to HEF Kutter;)!

If the only thing that is an issue is the bucket dump, has the bucket cylinder been checked out?
 

Kutter's

Member
Welcome to HEF Kutter;)!

If the only thing that is an issue is the bucket dump, has the bucket cylinder been checked out?
so i went out and messed with it today now its wanting to die anytime i do a fuction so im thinking maybe pumps stuck at full stroke?
 

Kutter's

Member
Yes sir I checked them all there was a bigger fuse in f7 I believe so I’m assuming from what I’ve read you post it probably fried it ?
 

Kutter's

Member
Pull the top cover off the PVC and look to see if the resistor is fried.

For a picture, see post #4.
I believe it was put into limp mode someone went out to work on it I pulled the plate down on the pump with the rod not sure the exact name. And it was facing towards the engine. Is that limp mode position? Or should it be facing towards the outside of the machine
 

Diesel Dave

Senior Member
I believe it was put into limp mode someone went out to work on it I pulled the plate down on the pump with the rod not sure the exact name. And it was facing towards the engine. Is that limp mode position? Or should it be facing towards the outside of the machine
In normal operation the stop rod is facing towards the engine.
In “limp home“ mode the stop plate (with stop rod ) key #47 is turned 180 degrees so the stop rod is facing away from the engine. In this position the stop rod doesn’t allow the piston to travel full stroke limiting the flow from the hydraulic pump. This limp home mode applies to Hitachi excavator models EX 100/120/200/220 (-2 or-3) and Deere excavators 490E and 790E (high and low serial # ‘s)
The screenshot below shows stop plate (with stop rod) #47 in normal position.
.
1715260010200.jpeg
 

Kutter's

Member
In normal operation the stop rod is facing towards the engine.
In “limp home“ mode the stop plate (with stop rod ) key #47 is turned 180 degrees so the stop rod is facing away from the engine. In this position the stop rod doesn’t allow the piston to travel full stroke limiting the flow from the hydraulic pump. This limp home mode applies to Hitachi excavator models EX 100/120/200/220 (-2 or-3) and Deere excavators 490E and 790E (high and low serial # ‘s)
The screenshot below shows stop plate (with stop rod) #47 in normal position.
.
View attachment 311887
Thank you. How do you get the hole inside the pump to rotate the 180 degrees the the stop rod plate will bolt back up ?
 

Diesel Dave

Senior Member
Remove the plate (with stop rod) , rotate the plate 180 degrees.
When you put the plate back in place , the stop rod will now contact the bottom edge of the piston. Force the piston upwards as you put the plate back in place.
 

Kutter's

Member
Remove the plate (with stop rod) , rotate the plate 180 degrees.
When you put the plate back in place , the stop rod will now contact the bottom edge of the piston. Force the piston upwards as you put the plate back in place.
I can’t lie to you I can’t for the life of me get the rod back up into the housing rotated 180 degrees
 

Diesel Dave

Senior Member
Maybe there is control oil trapped not allowing the piston to move upwards.
Remove the (2) solenoids key #75 on top of the pump and see if that helps the situation.. see Screenshot below.
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1715274677004.jpeg
 
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