Help With Aux Hydraulic Plumbing - John Deere 690E LC

[ColeGobin]

Hi There, I recently bought a John Deere 690E LC excavator. I think it's a 1998? (but I haven't decoded the vin to check yet) I have installed a hydraulic thumb on the machine, now I'm looking for some help adding the aux hydraulics to the system. This machine does not have an aux valve on the main control valve, so I'm installing all separate valving.

Does anyone have the same machine as mine with aux hydraulics, that you could show me how they tied into the main hydraulic pressure and return lines? In the service manual I have found that there is a pressure test port on the main control manifold, but I'm not sure what size this port is / if it could provide enough flow.

Cheers
Cole

 

[mg2361]

Welcome to HEF Cole!

Try contacting these companies to see if they still offer anything for your machine.

https://www.hctkits.com/excavator-kits/

www.hkx.com

 

[ColeGobin]

Thanks for the links! I've reach out to both companies to get a quote. My last quote from a different company was just under $4000, and that's me doing all the plumbing from the base of the boom to the thumb cylinder, and me providing the joystick with switch. That's just more than I want to spend on an old farm machine. So far I have bought all the valves (relief/ anti cavitation, directional control/ and pressure reducing) to do the kit myself for less than $1500. That's why I'm hoping someone with the same machine can show me how their kit ties into the machine, then I would know if the flow from the test port was enough, or is there another port on the machine that I'm missing.

Cheers
Cole

 

[ColeGobin]

Quick update for anyone else doing this. I ended up doing the whole thumb plumbing system myself. I ended up teeing into one of the two main 1.25" hydraulic feed hoses that run from the pump to the manifold. I unbolted one of these feed hoses from the manifold, bolted on a 1.25 CAT 62 flange to JIC adaptor on the manifold, added a JIC fitting tee to that, then cut the CAT 62 flange end off the hose and had a JIC end crimped on an connected that to the tee. In the end this gave me a JIC tee connection into the ~5000psi system pressure. I'm sure there are other ways of doing this, but this worked out well and the fittings were in stock at the hydraulic shop. From there I added a pressure reducing valve, directional control valve, and a cross over relief with anti cavitation check valves (has a tank port on the valve) and that feeds A+B to the thumb cylinder.

here is my valve bank if it helps anyone

 

[jacob D nichols]

Quick update for anyone else doing this. I ended up doing the whole thumb plumbing system myself. I ended up teeing into one of the two main 1.25" hydraulic feed hoses that run from the pump to the manifold. I unbolted one of these feed hoses from the manifold, bolted on a 1.25 CAT 62 flange to JIC adaptor on the manifold, added a JIC fitting tee to that, then cut the CAT 62 flange end off the hose and had a JIC end crimped on an connected that to the tee. In the end this gave me a JIC tee connection into the ~5000psi system pressure. I'm sure there are other ways of doing this, but this worked out well and the fittings were in stock at the hydraulic shop. From there I added a pressure reducing valve, directional control valve, and a cross over relief with anti cavitation check valves (has a tank port on the valve) and that feeds A+B to the thumb cylinder.

here is my valve bank if it helps anyone
View attachment 267631

We plan on doing the same thing... two questions. 1. What is your hose size for your pressure? Is it 3/4" for the whole system? 2. is that a closed center valve (closed between T &P)?

 

[ColeGobin]

Yes it's a closed center valve. I used 3/4" hoses for the whole system, even running up the boom and stick. And the pressure relief valve I selected was limited to 25 GPM. One thing that I've noticed is this thumb circuit doesn't trigger the main valve body/pump to increase flow/rpm. So the thumb is fairly slow if it's the only function you're using, but as long as you're using some other function at the same time the thumb has good flow / speed.