Help Fixing up a John Deere 992elc

[mattwaage1]

Hi all!
Well thanks to everyones good advice i abandoned the case 9050b from the earlier post and found a well loved but decent john deere 992elc.
It starts and runs, i loaded it and took it home already. It was a big bigger than i wanted but the price was great as i got it for almost free.

Its sat for a while and i have started replacing hoses and it needs a hydraulic cooler, the one is rusted and has holes. I bypassed it for now.

Anyhow, heres the few questions i have.
The former owner states that the machine was parked due to some slow hydraulic performance.

With a bit of testing it appears to me that swing is very slow and left track seems underpowered also. I have read aboit being able to do some testing on the pump solenoids? Any advice where to start?

Second, the electric throttle has been replaced with a push pull type cable. The factory electric control is not around now so i dont even know what the parts are to replace.
1: is the electric throttle needed? Does it provide input to the pump computer or anything that would cause slow performance or am i ok just using a throttle cable and not having the work modes or auto idle?
2: anyone have a picture of the electric throttle so i can see what parts i am missing and price them out?

The hydraulic cooler is trashed on this unit and bypassed to run it on and off the trailer. I have a line on some new ones for about $1100 delivered. Any better options?
I am looking to run a mulching head on this that will run about 100gpm so i would like to order 2 and install them to make sure the oil does not overheat from this load.

Last question for now: i would like to add a thumb to use also. Any way to run a hydraulic thumb and the hydraulic mulcher head at the same time? Or am i better off with price and simplicity with just a mechanical thumb? This will be used for vegatation and forestry so being able to handle and control brush and trees would be handy.
I heard there is a way to change the auxilary hydraulics from one way to 2 way quickly on these.models?

Im sure i will have a few more questions in the future but thanks for everything now! Ill add to this as i get things figured out and solved!

 

[Delmer]

Well, you're not afraid of much are you?

I can't help with the questions, but I'm sure a service manual would be a good step. I sure wouldn't spend a penny on an oil cooler until you know the machine will work. Bypassing the cooler is fine for what you're doing, which is diagnosing the machine. The service manual should give you a good enough understanding of the machine to precede with more confidence, not that you need any

 

[mattwaage1]

Haha well i already ordered the cooler a few days ago so it should be here soon.

I will be putting the throtttle cable in this weekend but hooefully someone can chime in with how the motor is supposed to mount and if we really need it.

Itll get running one way or another i know ive seen the posts on this forum and there are lots of smart guys with great advice!

I guess now looking for what to look at for a slow swing and slow left track?

 

[mattwaage1]

Sure quiet around here!

Anyone?

 

[thepumpguysc]

No electronics on the inj. pump.. manual throttle cable is ok.. just no auto idle & work mode.
Just make sure to adjust the cable to where you get full throttle travel at wide open throttle.. [hitting the stop screw]

 

[Vetech63]

You can run with a throttle cable set up but like Pump Guy said, your work modes will not work in conjunction with your engine. You would have to have the electronic throttle set up to gain your work modes since everything is regulated by ECU and Hydraulic sensor inputs.

 

[cuttin edge]

992.....that's like a 400 Hitachi isn't it. Seems to me that one of the companies I worked for in the 90's had a 400 with a bad pump. The swing and travel in one side were almost non existent

 

[sawdustmaker]

I think you would want to have two pump flow to a mulching head. Im not sure how that valve bank is set up and what you would have to do to get two pump flow without sacrificing the speed of another function. I believe processing heads usually use the arm circuit to achieve two pump flow to the auxiliary and put the arm on the spare.
One pump would be fine for a thumb but there may not be enough spools for both thumb and mulcher separately. Of course you can run them off the same lines if you arent using them both at the same time. But if you are using a thumb and bucket then you would not want to lose your arm speed and would need to switch the spools back. This could possibly be made relatively painless with some planning ahead.

 

[mattwaage1]

Hi everyone thanks for all the replies.
I got the flu pretty bad last week and it knocked me out of the loop and ive been playing catchup.

Ok, got the throttle cable installed today so i can rev it up and it purrs nice.

All fuctions seem to operate in a reasonable manner except swing in both directions and the left track are slow.
Swing is about 30 seconds for one revolution.
Left track doesnt move on its own if the pedal is pressed. It will move and travel if both pedals are depressed but will not counter rotate or steer from the left track.
When i say left track i mean the one under the cab if you are going forward.

So i have the parts and operators manual r this but did not get a service manual unfortunately so hopefully some of you guys can give me some pointers what to start testing. The sensors on the pumps kinda look like a mess from someone doing some hack repairs on them. Ill post a pic.

Im taking a rough guess that the pumps are not stroking properly when commanded for these functions.

So what sensors are responsible for swing/left track and how could i start checking them?

Thanks in advance! Back to take a nap to kick this influenza B.

 

[sawdustmaker]

:Edit They left you quite a mess there in that wiring. Maybe the issue is just a solenoid. I hope so for your sake but if it was parked for this issue, i would have to think its doubtful.

The swing and left track are driven by one pump and the right track is driven by the other. Boom, Arm, and bucket share both pumps. I would recommend checking the pressure and isolating which pump you are having a problem with. You can switch the pump outputs and see if the problem moves to isolate the problem to a pump/pump control. If you switch the main pump lines you also have to switch the load sense lines. That being said i have never done that on a machine this big. It may not be doable.

 

[typ4]

Look behind the seat for the computers, one is for engine and one is pump control. They talk to each other. You really need a service manual. I know on our 790 ELC there is no way to run the pumps mechanical. the solenoids are there to destroke the pumps.

 

[wornout wrench]

First thing that I would be doing would be to pull the return filters and have a look, see if there is any brass in it.
Then I would do a case drain test on the pumps. If one pump is spewing out the case drain, it is probably bad and not much you can do about that besides replace,
The wiring to the pumps can cause all kinds of issues, lots of small wires and they get old and brittle and will tend to break. You could have a bad angle sensor or high pressure sensor.

Do the case drain, that will tell you lots right there.