Ford 1700 3 pt lift problem

[JC-jetro]

1-Ok the main pressure line connecting to aux block next to pressure relief device is a solid line with the banjo. Can you verify the below pictures t what you have.

Last pic shows the pressure line banjo connecting to pressure relief. This the one and only pressure line to pressure relief.

2- Flow does not mean pressure if the pump is tired (worned out seals and gears).
3- Having zero pressure at the gauge location on my pic is troubling. there would be two scenarios there, it is either all the flow is bypassing at the relief to tank( diffy Housing) or pump is very weak and cannot fight against the stiff spring in the pressure relif to make pressure.
4- What does not make sense is you have zero pressure at 3 point but have 1500 to 1000 psi at the other block for steering and loader.
5- Hydraulic noise you are talking about , is it chattering at the relief device? if you raise your 3 points all the way up then you are dead heading the pump and the chatter is to lifting off the poppet to release excess pressure to avoid harming the pump.

6- it seems you have flow and must have pressure at the loader block so the pump appears to be good. seems somehow the flow is diverted back to the tan before serving the 3 point lift.

Look at my comment to see if a ring bells, this is a but of mystery that we need to sort out.

 

[Marinemammal]

1. The banjo fittings are all like they came out of the factory--just like in your photos.

3. We backed off completely from spring tension in the pressure relief valve and the gauge did not move off zero.

4. And why aren't the loader and steering working if there's pressure to that block.

5. The hydraulic noise is kind of a chattering squeal like auto power steering when low on fluid. It seems to be coming from the back and can be felt in that pressure line between the blocks.

6. I have been into the guts of it 2 years ago when the hydraulics quit then. It all seemed good--o-rings, springs. I don't know how that all works--just keeps the 3 point arms where you set them. I get the feeling that something is wrong in there, but then it used to just take an oil change to get it back in working order. This has been a mystery for 15 or 20 years, but now the magic fix didn't work...

I haven't had that valve apart that is next to the 3-point lowering speed valve--springs and balls. I will do that next. What does that do?

 

[JC-jetro]

I haven't had that valve apart that is next to the 3-point lowering speed valve--springs and balls. I will do that next. What does that do?

1-if the spool valve has a neutral position. It is operated by a linkage that ties the lift arm to the spool cover. How it works is when 3 point reaches the required height and as the arm goes up it slowly diverts flow in to the tank and stops the flow to the cylinder. so if you remove the cutter pin and turn the tractor on the arm should go up and as it hits the top then pump is dead headed and the chatter starts. if you do that test, watch your finger not be close to lift arm and that linkage,just shut the tractor and then re-attach after all movement stops. if the spool valve constantly by passes then you would not any pressure at the gauge.
2- The balls and two spring works as such. The bigger ball and spring is actually a check valve and adjust rate of drop (rabbit/turtle) knob. The smaller ball is over pressure shock relief to protect the seal. if that is open it will internally leak the fluid in to diffy housing. if that is so the flow is all diverting the 3 point but I would think the gauge should show residual pressure under flow. it is essential for you to check that out.
3- it appears your pump is working and it might be you left spool that is faulty and that is a difficult thing to repair or source.

Do some more digging and report back.

JC

PS. actually you need to add to spring tension by dialing it to increase the pressure and not the way around. Try to turn it in as far you can without messing up the thread and don't force it. on some tractors they use shims (washer) to adjust up pressure by adding shims or reducing shims to lower pressure. did you see the conical poppet? I had a pic somewhere and have not been able to find and post yet.

one other thing, try to open the plug where I have the gauge. You should have flow there. Get a bucket and try to see if you have flow there. Bucket to control the spillage.

 

[JC-jetro]

I knew had the pic and needed to find it, pic is below, do you see the the conical valve called poppet. That is essential to build the pressure.

 

[Marinemammal]

There's actually another part for this pressure regulator. There is a cup with some holes on the sides and a place for the poppet to seat. It didn't come out with the spring and poppet--not even with a magnet. But it did come out when we ran some oil through the regulator and got hung up in the funnel--luckily enough.

 

[Marinemammal]

1-if the spool valve has a neutral position. It is operated by a linkage that ties the lift arm to the spool cover. How it works is when 3 point reaches the required height and as the arm goes up it slowly diverts flow in to the tank and stops the flow to the cylinder. so if you remove the cutter pin and turn the tractor on the arm should go up and as it hits the top then pump is dead headed and the chatter starts. if you do that test, watch your finger not be close to lift arm and that linkage,just shut the tractor and then re-attach after all movement stops. if the spool valve constantly by passes then you would not any pressure at the gauge.
2- The balls and two spring works as such. The bigger ball and spring is actually a check valve and adjust rate of drop (rabbit/turtle) knob. The smaller ball is over pressure shock relief to protect the seal. if that is open it will internally leak the fluid in to diffy housing. if that is so the flow is all diverting the 3 point but I would think the gauge should show residual pressure under flow. it is essential for you to check that out.
3- it appears your pump is working and it might be you left spool that is faulty and that is a difficult thing to repair or source.

Do some more digging and report back.

JC

PS. actually you need to add to spring tension by dialing it to increase the pressure and not the way around. Try to turn it in as far you can without messing up the thread and don't force it. on some tractors they use shims (washer) to adjust up pressure by adding shims or reducing shims to lower pressure. did you see the conical poppet? I had a pic somewhere and have not been able to find and post yet.

one other thing, try to open the plug where I have the gauge. You should have flow there. Get a bucket and try to see if you have flow there. Bucket to control the spillage.

I will try to see if there is some flow out of your gauge port tomorrow. Also I will take that apart on the other side of the 3-point down-speed adjuster to see if the springs and balls and o-rings look good.

 

[JC-jetro]

I will try to see if there is some flow out of your gauge port tomorrow. Also I will take that apart on the other side of the 3-point down-speed adjuster to see if the springs and balls and o-rings look good.

ok. sounds good. On the other side of the 3 point lift piston, left of the operator, make sure not to lose springs and balls and with assembly removed and you turn the tractor on you should get flow of hyd oil coming out. if you do tat test make sure the cap where the pressure gauge is put back in. we just need t verify how far down the system you get flow. if you get flow, keep the bucket there for 15 to 20 secon as you might have some contaminant that you might be able to expel, same as kidney stone,

if you have flow then put all back to see what pressure you have if any. You can turn the adjustment on the relief clockwise and have someone watch the gauge as you do it to see if pressure goes up. good luck.

 

[Marinemammal]

The springs and the balls and the o-ring looked in good condition. Briefly there was a little oil that flowed out through that port when the tractor was started. I ran it for 2 minutes and no more oil came out. Then it was reassembled

I did get a continuous trickle of oil out through the gauge hole when the gauge was removed.

I turned the regulator all the way in (about 6 turns), but got no response on the gauge. P=0. I returned it to where it was--about 2 turns after making contact with the spring.

I did measure pressure in that same gauge hole a couple years ago, and had to move the position sensor lever before the pressure went up to 1500 or so. I tried that a few days ago and got no response.

The fluid noise increased when trying to turn the steering wheel, and actually could turn it a little.

After it was all back together--gauge still in the place--The 3-point came up slightly when started then a little more after a couple minutes. It wasn't coming up slowly, but would make jumps periodically until it was all the was up after about 8 minutes. The 3-point felt a little spongy--i could push it down a couple inches. I did put my whole weight on it and it didn't go down.

I did get the loader to come up a couple inches by continuously holding back on the control lever. But it wouldn't come up any more than that. And that happened in just one move--not a slow jerky move.

I was able to turn the steering wheel and move the front wheels a little, but could not get that to happen again.

I am not sure what the spool valve refers to. I think it might be in the attached parts diagram. I was into this a couple years ago and everything looked good. There were some parts missing, but it has worked since I discovered that. My repair manual says that if you have the 21 spring you don't need the 23 spring. And the 22 plug and the 24 spool are also missing. At the time I tried to buy the missing parts, but they weren't available. So I bought a used one of these whole control valves, and it also had the same parts missing so I returned it. I have a list of the parts in the diagram if you want to see that.

I did try getting a pressure reading while pulling the cotter pin from the position sensor for the 3-point. The 3-point came to the top immediately and went down when I moved the lever, but it did not come back up when I released the lever. There was no change on the gauge.

 

[JC-jetro]

The springs and the balls and the o-ring looked in good condition. Briefly there was a little oil that flowed out through that port when the tractor was started. I ran it for 2 minutes and no more oil came out. Then it was reassembled

That is exactly how it should have operated. Basically tried to fill the lift cyllinder cavity and then spool went to neutral position and dumped all the oil inside the diffy as I explained below

I did get a continuous trickle of oil out through the gauge hole when the gauge was removed.

That is normal too. Did you manipulate the lift lever up and down? doing so it should have increase the flow some. Forgot to ask you previously to do so.

I turned the regulator all the way in (about 6 turns), but got no response on the gauge. P=0. I returned it to where it was--about 2 turns after making contact with the spring.

-That is not very good result but it is not all conclusive that the pump is bad yet. The flow might be by-passed from spool to the diffy or tank. will explain a bit later at the end.

I did measure pressure in that same gauge hole a couple years ago, and had to move the position sensor lever before the pressure went up to 1500 or so. I tried that a few days ago and got no response.

The position sensor level is connected to the spool valve. Guts of spool valve is just on the right side of seat internal to diffy housing. Pic below. when position lever pushed up it allows flow to the piston and when you lower it allows flow back to the spool that is then diverted to diffy housing or tank

The fluid noise increased when trying to turn the steering wheel, and actually could turn it a little.

That's normal. turns a bit means you have flow and that mean pump is working. Now the question is the flow has much pressure or not. it takes a lot less flow for steering as you just flood one small piston and not a lot of volume. one can deduct that pump is tired some like I said before bad seal or mating gears worn out.

After it was all back together--gauge still in the place--The 3-point came up slightly when started then a little more after a couple minutes. It wasn't coming up slowly, but would make jumps periodically until it was all the was up after about 8 minutes. The 3-point felt a little spongy--i could push it down a couple inches. I did put my whole weight on it and it didn't go down.

3 point coming up is good even if slowly but how can you explain zero psi at the gauge while going up? this could potentially be spool that is leaking and bypassing flow away from 3 point. Pushing the 3 point down by hand could be caused either by piston seal is leaking or spool is not holding the pressure. The rate of drop knob on the seat is the passage way for the hyd oil to enter cylinder cavity or expel the fluid back the same way to the spool to be dumped in the differential housing.

I did get the loader to come up a couple inches by continuously holding back on the control lever. But it wouldn't come up any more than that. And that happened in just one move--not a slow jerky move.

That cud be indication of the pump is working but it is weak. The flow and pressure has to fight gravity and the bucket. It needs good flow and pressure to work. if you did not have flow you could not raise the loader. You have that but if pump is weak it will struggle like it appears it is

I was able to turn the steering wheel and move the front wheels a little, but could not get that to happen again.

flow and pressure like I said above.

I am not sure what the spool valve refers to. I think it might be in the attached parts diagram. I was into this a couple years ago and everything looked good. There were some parts missing, but it has worked since I discovered that. My repair manual says that if you have the 21 spring you don't need the 23 spring. And the 22 plug and the 24 spool are also missing. At the time I tried to buy the missing parts, but they weren't available. So I bought a used one of these whole control valves, and it also had the same parts missing so I returned it. I have a list of the parts in the diagram if you want to see that>

The picture you have shows the spool valve. Yo see there two spools or round pencil like rod. It has close tolerance with the body of the valve and seals and film coefficient of oil between highly machined spool and body does do the diverting of flow toward 3 point and then dumps unused portion of it to the diffy. There is linkage on the valve inside ( see the pic below) that is cnnected externally to the lift arm. That is part ofthe dump linkage to allow the fluid to return to the diffy. This is constantly going as you have live hydraulic, meaning flow anytime the engine is on. Once 3 point reaches the desired height then fluid is trapped in the cyliinder and all the flow is returned to diffy.

This the spook valve on the inside. it can be withdrawn from the outside but all the bracket along with pressure relief valve need to be taken off. Repair of the spool is not easy as sourcing that spool on a rig that is 40 yrs old is difficult. specialty hydraulic shop might be able to do it but it is hit and miss.

All and all based on all you have examined I think it is higher likelihood that the pump is weak. the thing is what guarantee you have that the pump you got was as good as oem. Was the pump overhauled? was it new or used. I have overhauled my pump and it is quite simple if you can source the overhaul kit. when I did it it was about $35 for the kit and an additional shaft seal about $8. I think that was about 15 years ago and the pump works like a champ.


As they say, no good deed ever goes unpunished. Working the spool could be quick sand as it is difficult to open it up non-destructively so once you commit you have to go all the way. Pump on the other hand can be taken off and inspect without damage if you have the patience. I still have my old seal saved in a plastic bag immersed in oil My problem was the shaft seal. I replaced all since I had the part and could do it. I have pump breakdown picture if you decide to give that a go. one last thing , if the fluid is old then changing out along wih cleaning screen might be a cheap thing to do specially if you use an oil that is proven. The one i got from TSC has proven it to me to be a good hyd oil.

JC,

 

[Marinemammal]

I bought the pump new from Legacy Hydraulics in July 2018. It has about 60 hours on it. I have contacted them to see what they can offer. At the time I had taken the original pump apart and found scratches on it that were an indication that it was shot. So I bought the new one for about $500. However, since that time the tractor has cycled a couple of times through the hydraulics quitting and being fixed by simply changing the oil. The pump would be the easy fix, but expensive, unless it can be rebuilt. Or maybe I should rebuild the old one since I believe it was the original Ford pump. I forget now where I got that information, but scratches on the inside of the pump was bad news.