Add auxiliary hydraulics to john deere 490e excavator

[68raisin]

Good day 68
Your plan is to control the thumb by buttons on the R.C.V. that will require a reversing soleniod valve or two sepererate valves these will require relays to prevent the switch taking the load, note that will be an On-Off sytem (No proportional control) be sure this is what you are looking for as most operators prefer proportional control. Those blank plates are the main lines to use for an option such as thumb our suggestion is that and auxillary in line relief be installed to the positive side of the thumb to just provide enough force to retain material preventing overload.
If you have a read of those PDF's posted it will give you a better idea of what options are open to you, if you need specific instructions drop us a line happy to help.
Kind regards
Uffex

Thank you Uffex for the reply! I am unable to see any of the attachments that you post. Probably something on my computer.

 

[excavator]

I planned to plumb the thumb where the block off plates are and use a D03 valve controlled with buttons on the joystick.
1. Do I need to add external pressure relief (as it does not appear to have this on the main valve)?
2. Do the pilot lines go in place of the jumper hose seen in the picture supplied by Everytime5.9?

Chad

Yes, you need to have reliefs on both lines going to the thumb. Either installed in the control valve or you can buy a relief block and install it in-line on the boom. Factory reliefs are the best way but that requires buying 2 from the dealer. The pilot lines to control the thumb need to go from the DO3 to the control valve, one to the top and one to the bottom. If you look at the control valve you will see small 1/4" lines coming from under the cab running up to the valve. Some models go into the front of the valve spool housing, some go to the top. There should be a plug in the spool housing auxiliary section which you remove and replace with a JIC fitting. Check the Deere parts site as sometimes the top fitting is a special fitting. If I have time later today I will look as I made drawings ect. for the thumb installs I did in the past. Are you in Poulsbo Washington?

 

[68raisin]

Thanks excavator! I have never used relays either and rarely had switches fail. I have not used proportional control for thumbs and don't care to. The ex120-2 is new to me and I am unfamiliar with Hitachi/john deere so was unsure of how the main valve worked if there was any built in relief for the circuit I'm trying to use. Sounds like I need to get an inline relief valve to allow the bucket curl to overcome the thumb.

Q; When the thumb is pushed back by the bucket will the main valve fill the vacuum on the other side of the thumb cylinder?

 

[uffex]

Good day 68
There seems to be an issue with PDF files at this time I to have had issues with Firefox not sure if it is but I found dragging the file onto the desktop solved the problem or you can download the file is on the web site free at excatech.org.
I have taken excavators coimments on board and to a certain extent agree as I assume the comments are refering to proportional electric valves (Control by PWM signal ) proportional control refers to the normal excavator pilot control be it foot pedal or cross directional valve i feel it is correct to point this out and avoid misunderstanding. It is possible to control the thumb within the normal two pattern control and remain with proportional regulation the choice is yours. With regard to relief valves what is worthy of consideration is the thumb cylinder can generate high flow and high pressure on the positive side when the force has been generated from the bucket cylinder normal factory port relief valves are low flow high pressure not capable of offering the correct protection.
Kind regards
Uffex

 

[68raisin]

Yes excavator, I'm in Poulsbo. I talked to JD yesterday and it doesnt look like there are provisions to add relief valves to the aux section. I think the other connections are straight forward enough.

 

[68raisin]

Oddly, with my screen maximized, the pdf attachments are not present. If I minimize the screen the links to the pdf's magically appear! Thanks for all the information

 

[excavator]

Yes excavator, I'm in Poulsbo. I talked to JD yesterday and it doesnt look like there are provisions to add relief valves to the aux section. I think the other connections are straight forward enough.

I will have to look on the Deere website but I'm sure there are provisions in the control valve for reliefs in the auxiliary section. I'm about 2-3 hours north of you up by the Canadian border and I'm quite sure I have more than a few Deere/Hitachi reliefs lying around that would work. Other wise a relief block on the boom works, I'll do some checking and try to get back to you.