I read thru numerous posts yesterday from the search engine, but I am still a little unclear on somethings. I have a JD 4640 Powershift recently purchased. Tractor is rough but runs and shifts good as I just finished discing and planting 100 acres of wheat. I have not tried the 3 point hitch except for when I was buying it with no load on it. Here is the situation: after planting 100 acres with the 750 notill drill and running the first hydraulic lever in the continuous (forward position), I noticed the steering wheel shake/vibrate at idle while hooking up a pto ditcher. No problems after the engine is revved up or running down the road. I also noticed the lift shake as it comes up. I did not get to ditch with this tractor or run it this weekend after getting the ditcher hooked up. This tractor was used for mainly bushhoggin and light discing for the 4-5 years before its owner passed away where the engine was rebuilt just before he got it. It appears that this could be anywhere from fliters being clogged, the screen or the pump starting to go bad. Since the tractor has been sitting for several years and not heavily pulled, I am betting the continous flow on the hydraulics cleaned the system and loaded the filters. So here are some questions:
1) On the attached picture, I assume the destroke valve is suppose to be on the top where the line goes to an accumalator. If not, where should it be and do you see one in the pic?
2) On the attached picture, where is the spring loaded valve that farmer45 mentions here:
" farmer45 - 10/1/2011 20:01 I have a 4240 that has lost hyd power a couple of times. I'm not an old JD man so I don't know if a 4430 would be the same or not. My tractor isn't home now so I can't look at it to tell you where things are for sure. On the top of the front pump there are two plugs. I think they are on the left side. I think that under the smaller one there is a valve that is spring loaded from the bottom. With the plug out I droped a punch in the hole and tapped on it gently, Don't hit it so hard that you damage it. There must have been something that caused the valve to stick and after I tapped on it it worked fine. After a couple of years it did it again and I did the same thing and it is still working fine.There isn't anything under the plug to jump out and get lost."
3) when changing the fitlers, I assume you will loose all of your hydraulic fluid as you remove the filter. Any tricks to doing it with out draining the system? i think it holds like 15 gallons
4) I need to change the pto seal out, can it be done without draining system.
5) When hooking up a gage to the scv, do you just get one hose with pioneer coupler hooked to the gage and place it in one side?
6) When you destroke it, do you screw it in with the engine running at 1500 rpms until you hear the pump change sound and then turn it back? How long do you pause at the sound change?
7) Where is the hydraulic screen that should be checked/cleaned?
8) Anything else I should be aware of???
I will respond on all my findings so the next search someone does hopefully can answer their questions.