Ford 1700 3 pt lift problem

[JC-jetro]

Below is the what a good pump should be like. I ended up overhauling it because I was able to source the kit. My shaft seal was bad that was not art of overhaul kit. At this point it appears the simplest , least costly attempt is to change the oil with something batter perhaps. That would be around $60 perhaps and even it that does not solve it still it is money not wasted. The only thing with the pump inspection is you can do it non-destructively. What you see on the pic where old seals and they really did not look bad on mine and I bet it would still worked. if you can find the old pump then post pocs here to take a look at. May be overhauling it without messing with your existig pump would be a good option.

 

[JC-jetro]

Ijust thought of something else. look at Post #39 and the second picture. That is the spool on the inside of diffy. The hole on the block is where hyd fluid is routed to the lift cylinder. if you remove the head and turn the tractor on, then there should be some fluid coming out of that hole but you will have an steady flow of fluid dumping off inside the diffy. Reason behind that is the spool is in it's neutral position for the given height and the rest of the flow , like in my case without loader constantly is dumped back to the tank. You have an open center hyd system and the fluid is constantly pumped without stop as long as the tractor is on. it is either used in my case only when I use the lift and 99.9% of time dumped back in to the tank to complete the circuit. That could be one other alternate method to test the pump for flow. Make sure the ram rod that pushes the piston up does not hit the inner housing, in other words don't manipulate the 3 point by raising and lowering, the purpose here is just to check the flow.

 

[Marinemammal]

I tried the flow test before taking the pump apart. I get nothing out of the hole the feeds the cover for the 3-point piston/cylinder. Right after starting there is some flow inside, but I think it's coming out of the return lines from the steering and loader. That quits almost immediately, and there is no other oil flowing in there. I'm not sure where the oil would be coming out of that control valve. There is what looks like some splashing coming from below. It must be the pto shaft linkage down in the oil even thought the pto is not engaged.

 

[JC-jetro]

I tried the flow test before taking the pump apart. so, did you take the pump apart?

I get nothing out of the hole the feeds the cover for the 3-point piston/cylinder. That's okay, but as yo raise the lever it will feed fluid and then it stops at neutral position. It is always splashing all return fluid from all hyd (loader steering and 3 point) back to spool valve and returned to diffy.

I'm thinking that hole in the cover should have an o-ring, but there is none. it does have an o-ring look at the pic below of cylinder head.

Right after starting there is some flow inside, but I think it's coming out of the return lines from the steering and loader. That's right.

That quits almost immediately, and there is no other oil flowing in there. if you mean flow from spool in the diffy then that is an indication the pump is not pumping. Let's be clear, you have the cylinder head removed, started the treacor and would not see any oil being splashed inside. is that correct?

I'm not sure where the oil would be coming out of that control valve. Not sure exactly where yoy are talking about. The control valve always should see full flow. it is either going to a device or return to diffy. flow is always constant.
There is what looks like some splashing coming from below.Explain where you mean by below.

It must be the pto shaft linkage down in the oil even thought the pto is not engaged. I can see any association. PTO gear and coupler are immersed in the sump and in a oil bath. that has nothing to do with pump flow. I am not clear on you what you mean.

 

[Marinemammal]

I found the o-ring--underneath the tractor. Should I try to raise the three point control lever to see if oil comes out of the hole to the cover/cylinder head? The cylinder head is removed, tractor running, and the only movement of oil inside there seems to be splashing from below-which is where my drawings say the oil is dumped when in neutral position or when lowering the 3-point. But I can't tell if it's from the valve or from the pto turning and splashing. Would it be running out of the valve fast enough to look like splashing?

I did get into the old pump and posted some photos. Mine does not have that key (like in your photo) that fits in between the bearing pieces--although there is a place for it. Not sure why it would be needed. There's no place for the pieces to go. There is some wear in the body where the gears run on the inlet side. You can just barely feel it with your finger.

 

[JC-jetro]

I found the o-ring--underneath the tractor. Should I try to raise the three point control lever to see if oil comes out of the hole to the cover/cylinder head? yes, You can do it. watch the ram rod , don't get you r finger in there and may be have someone to have shop rag in front of the hole to avoid making a mess. It must flow some oil and then stops at neutral position and divert the flow back to diffy.

The cylinder head is removed, tractor running, and the only movement of oil inside there seems to be splashing from below-which is where my drawings say the oil is dumped when in neutral position or when lowering the 3-point. But I can't tell if it's from the valve or from the pto turning and splashing. Would it be running out of the valve fast enough to look like splashing? That is good. it has nothing to fdo with PTO non whatsoever. It is a coming from a port on the valve body. it does have a snout or anything to have steady garden hose like flow and it hist the inside of the diffy and goes every where where off course ends up in the floor of diffy where yo screen and pump suction pipe is.

I did get into the old pump and posted some photos. Mine does not have that key (like in your photo) that fits in between the bearing pieces--although there is a place for it. Not sure why it would be needed. There's no place for the pieces to go. There is some wear in the body where the gears run on the inlet side. You can just barely feel it with your finger. it does not look that bad. Make sure put witness mark on bushing and gears and how they all went together. Those parts are mated together and have a better tolerance. use highest grede emery cloth and some hyd oil and very gently smooth out the pump inner body where the gears move against. Take off any burrs that you see. be extremely gentle and take as little as you can. Hopefully you have enough tolerance and oil film to give the pump good efficiency. The pump is better looking than i anticipated. I don't know how many iteration of that pump were there but keepers mayor may not be necessary based on design.Main input sahft and gear for sure need to have a keeper as the torque is high.Most other pump othetr than hysraulic have the shaft keeper.

 

[Marinemammal]

I did that test again running the tractor with the head off. This time there didn't seem to be any movement of oil inside there. I put my hand in there to see if there was oil coming out the bottom of that control/spool valve--nothing. No splashing. I moved the 3-point lever and nothing happened. That connecting rod will not move without the piston being in place. There doesn't seem to be any pumping going on anywhere. I don't know what happened to the splashing.

Where did you get the pump rebuild kit?

 

[ROUSTABOUT]

3 pt will drop when engine is turned off and load is on 3 pt. When I start engine the 3 pt will lift blade but pulsated up and down an inch or two. Shut off the engine and the lift drops slowly and I hear a clicking noise from the area of the relief valve. What could cause this problem?

Unscrew the knob under the seat. Or you may have to loosen nut just behind knob. Take it out and replace the o ring on it. It's special so stop by the dealer.

 

[JC-jetro]

Unscrew the knob under the seat. Or you may have to loosen nut just behind knob. Take it out and replace the o ring on it. It's special so stop by the dealer.

that is just the knob that regulate how fast 3 point drops, basically it restrict trapped oil in the lift cylinder back to the tank via spool valve and really has nothing to do with the pumping of the oil.

 

[JC-jetro]

Unscrew the knob under the seat. Or you may have to loosen nut just behind knob. Take it out and replace the o ring on it. It's special so stop by the dealer.

I did that test again running the tractor with the head off. This time there didn't seem to be any movement of oil inside there. I put my hand in there to see if there was oil coming out the bottom of that control/spool valve--nothing. No splashing. I moved the 3-point lever and nothing happened. That connecting rod will not move without the piston being in place. There doesn't seem to be any pumping going on anywhere. I don't know what happened to the splashing. I think there is great possiblity that your pum is not working well from all the test you have done. One last thing we can do on the pump without any valving or control. If you just folllow the banjo connection on the pump discharge which is the smaller dia all the way to relief device. If you take that banjo nut off and turn the tractor on then for sure you would have flow if the tractor is on. That is way before anythng that could manuipulate flow. If yiou do not have flow there then there is only two possibilities. 1- pump is bad and, 2- the pump suction is either blocked or restricted like having dirty suction screen. Again, having flow is one thing and having flow at pressure is a different thing. A weak pump can pump against no head but can fail against head. The relif spring stiffness is to provide resistance up to 2100 psi.

Where did you get the pump rebuild kit? I bought that 15 years ago from my local NH dealer that moved to another location much further from me. Then I boought it I think around $40. I'll search a bit, if I find a source then I will post it.