Hitachi ex120-2 travel speed issue

[maineplower]

When I change the track speed the green rabbit/turtle light changes but the track speed doesn’t seem to change. Any ideas what to look at? Thanks

 

[mg2361]

Check your fuses first. If all is good there then you might have an issue either with the two speed solenoid or a bad pressure switch/wiring on the main pump. If you have or know someone with Dr ZX or MPDr, that would make troubleshooting a whole lot easier.

 

[maineplower]

I don’t have the diagnostic tools. I will check the fuse. Where is the solenoid located? Thanks

 

[mg2361]

Do all the other functions work OK?

If the pressure switch on the pump sends a signal higher than is actually there might keep your travel functions in turtle mode.

There are 8 solenoids mounted in a valve on cab side next to the main control valve. The travel speed solenoid should be the front solenoid on the bottom row. It should be approximately 23 ohms if you measure the resistance.

 

[maineplower]

Yes all the other functions are fine. It seems to be stuck in fast speed

 

[mg2361]

If you are stuck in high speed then I would concentrate on the solenoid and it's wiring. A defective solenoid, no voltage to the solenoid or a stuck solenoid valve could keep you in high speed. Do you have hydraulic gauges?

 

[maineplower]

No I don’t have gauges. When I get a chance I will look at the solenoid. Thanks

 

[955cat]

No I don’t have gauges. When I get a chance I will look at the solenoid. Thanks[/QUOTE. What did you come up with on 120-2 travel speed stuck in high I’m having the same problem . thanks , Sam

 

[955cat]

. I’m having the same problem with 120-2 travel stuck in high , new to forum tried to post but didn’t show. What did you find was your problem ?

 

[maineplower]

I haven’t figured it out yet. Been busy with other things, I’m going to look at it soon. Let us know if you figure yours out.

 

[TVA]

Might be mistaken, but JD/Hitachi uses PWM to regulate the travel speed. Might be that driver or amplifier is malfunctioning and switched to full DC current.