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John Deere 135G / Hitachi ZX135US-6 attachment setting

Bullitt

Active Member
Joined
Oct 30, 2022
Messages
35
Location
Central PA
Occupation
Manitou / Gehl & Yanmar Tech, Rental Monkey
I installed a thumb and I can't get the settings right. It's a progressive lever thumb.
I'm trying to set it so that the bucket will overpower the thumb to avoid damage.
My settings options are:
Attachment relief valve: Both disabled / attachment relief is enabled / breaker relief is enabled
Attachment selector valve: C/V or O/T
Aux flow combiner valve: enabled / disabled
Attachment relief pressure: min 10mpa / max 36mpa

No matter what I do with relief setting setting the selector valve to O/T makes the thumb so weak its useless, and setting it to C/V makes it so strong it will overpower the bucket cylinder.

Does anyone have experience installing thumbs on these machines?
 

Bullitt

Active Member
Joined
Oct 30, 2022
Messages
35
Location
Central PA
Occupation
Manitou / Gehl & Yanmar Tech, Rental Monkey
Isn't this electronically control variable relief?
 

mg2361

Senior Member
Joined
Jul 5, 2016
Messages
5,287
Location
Pennsylvania
Occupation
Equipment Mechanic
Isn't this electronically control variable relief?
Actually, yes, it could be, depending on the serial number. The "E" serial numbers were mechanical. The "F" serial numbers, there was a serial break (unpublished) as to when they switched to electronic. Easy enough to check. Look at it. Wires or no wires?

Attachment relief valve: Both disabled / attachment relief is enabled / breaker relief is enabled
Set it to attachment relief enabled if you have the electronic relief.
Attachment selector valve: C/V or O/T
Set to C/V (control valave). O/T (oil tank) is for breaker operation.
Aux flow combiner valve: enabled / disabled
Set to disabled. This is for two pump flow, which you do not need for a thumb.
Attachment relief pressure: min 10mpa / max 36mpa
Most thumbs are 11 MPa (1700 psi) - 16 MPa (2300 psi). When setting the auxiliary relief pressure, don't assume the setting you pick it for will be 100% correct. Double check by dead heading the function and watch the pressure in the monitor.

Screenshot 2024-03-09 at 6.47.28 AM.png
 
Last edited:

Bullitt

Active Member
Joined
Oct 30, 2022
Messages
35
Location
Central PA
Occupation
Manitou / Gehl & Yanmar Tech, Rental Monkey
You are a incredible wealth of info mg2361.

I feel like a total idiot for messing with MPDr and the monitor for all that time Friday afternoon. I just seen this in ServiceAdvisor "The following procedures describe how to set, confirm, and adjust the aux relief pressure for an attachment. These procedures apply to machines with serial numbers 500187 and later" and my machine is #500017

What I find crazy is that there is no mention on how to adjust earlier # machines. Furthermore Hitachi manuals don't mention either early or late module procedures even as much as SA does.

I'm going to put eyes on the relief Monday and confirm its not electronic. Can't wait, this is the last thing I need to do to this machine after replacing the swing drive reduction gear box, replacing a track link, and a full fluid and filter replacement. Honestly one of the best T4F excavators I've put my hands on, so little issues with it and it has tons of ability.
 

Bullitt

Active Member
Joined
Oct 30, 2022
Messages
35
Location
Central PA
Occupation
Manitou / Gehl & Yanmar Tech, Rental Monkey
It's adjusted correctly now. It did not have electro-mechanical solenoids. The bottom one was a bit of a bear to get adjust correctly.

Thanks for your help guys! Feeling like a John Deere tech it's all I have been working on lately.
 
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