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Eastern Iowa | I'm starting this thread over, the first one is on page 3 now.
I have a 4430 Quadrange. It has a loader on it and the front pump has been cavitating when I start the tractor. We put the tractor on the MoCo the other day and after an hour or so the tractor lost hydraulic function. The driver unhooked the MoCo and was able to get the tractor home. We drained the oil, replaced the filter and checked the screen, it was clean. I cut the filter apart and found nothing to obvious. It sounded to me like a trans pump problem so I pulled out the trans pump hex drive shaft and it looked very good. Next I plumbed into the filter relief valve housing where oil flows out to the pressure control valve. We ran the tractor and filled a 5 gallon bucket in 30 seconds while varying the pressure with a ball valve. The flow remained consistent at various pressures. Next I put a hose gauge and valve on the high pressure manifold (square block on right side of trans case) I plumbed into the exit fitting after the manifold. There I had erratic flow and was unable to build pressure unless the valve was almost closed. If I closed the ball valve It would build pressure to about 2000 psi. From there I went to the output line on the pressure control valve (left side of clutch housing). I removed the line that goes between the pressure control valve and the main high pressure front pump and plumbed my gauge and valve in there. I had very poor flow, just a gallon or so in 30 seconds with no restriction and less when I restricted the flow. In the first thread KelB instructed me to put a gauge to the test fitting on the filter relief housing and not the rpm when got 10 psi. I got 10 psi at wide open throttle, (2500 rpm) and it dropped as the oil warmed. I activated the pto and pto brake as instructed and saw only a momentary change in pressure. I also operated the quad hi/lo and saw only a momentary fluctuation. by now the oil was heating and I was only running about 3 psi at 2500 rpm. Any ideas what I should do next, I'm not seeing where my problem is. I would buy a tech manual but they have to be ordered and I need it now. Yes that is also what I said 8 years ago when I had the whole thing torn apart. |
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| Did you check the screen in the main hydraulic pump?
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SE Nebraska | I have a 73 4430 that heats the oil and looses hydraulic function too. But it only does it when the three point is raised up. If I run it with the three point down all the way, it works fine and doesn't get the oil hot. My lift arms don't go up all the way and they chatter at their highest point so I'm thinking a problem in the rockshaft control valves. Will be one of my winter projects. |
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Freeburg IL | you need a destroking screw for the pump. Install the destroking screw, then cap the line in front of the valve bock on the right side of the trans case. start the tractor and listen with the destroke screw threaded out, then thread it in and listen for a change in the pump/engine sound. If there is a noticable change then the pump is the problem. often times the outlet valves in the pump. It is repairable. |
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Washington Co Ks | 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. |
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Faunsdale, AL | 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.
That should be the stroke control valve. It responds to pressure built up in the outflow of the pump. As long as the pressure there is below the setting, it should allow the pump to go "into stroke". Once the pressure builds up, it destrokes the pump by keeping pressure on the internal end (next to the cam) of the cylinders so that the pistons do not return once they are pushed out by the cam.
they do occasionally get some crud in them. It helps to have a manual destroking screw on the pump. Usually destroke it a couple times and it will clear out. Seems that there isn't much oil circulation through the valve housing and stuff accumulates in there. I remember taking one apart that had nasty old oil in it, but the oil in the system was clean. |
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4430 hydraulic system troubleshooting
