Ford 1700 3 pt lift problem

[Hooked_on_HP]

I am curious about the new style seal for the piston in the TPH. I replace mine about 3 months ago and it was the same one as in JC's pics. Is the new on an oring with a thin teflon seal along side of it.
Bill

 

[ComputerGuy]

Good advice! I checked the boots and they seemed okay. Someone told me that he has learned to put a 5 gallon bucket over the shift levers to help keep the rain off. He said that an amazing amount of water can get in through "weather resistant" boots and things!

 

[ComputerGuy]

I am curious about the new style seal for the piston in the TPH. I replace mine about 3 months ago and it was the same one as in JC's pics. Is the new on an oring with a thin teflon seal along side of it.
Bill

I wish I had taken pictures now! It was a bit hard to be the mechanic and the photographer too! But yes, it was an O-ring and a nylon/teflon seal -- two different part numbers. If you want I can go hunt the invoice and get the numbers...

 

[JC-jetro]

Texas Blues. I am having problems with my 1700. My gasket is there, but does not protrude out much at all from the outside of the piston. I would like to replace it. Where did you get yours?

You realize if this is a very old 13+ yr thread. Have not seen Tex for a very long time. By the way the pics he posted are of my Ford 1700. What is the nature of the problem you have.

JC,

 

[Marinemammal]

I have a Ford 1700. Besides the 3-point, it has power steering and a front loader which all run on the same hydraulic system. Eventually, the hydraulic system begins to make noise at the pump mostly and then slowly over time and use the hydraulic system quits altogether--no power steering, no lift on the 3-point, and no lift on the loader. Usually, by changing the hydraulic oil and cleaning the screen (not that dirty) everything would be good as new. Usually this takes several months to a couple years to run it's cycle. What seems to set it off is some serious pto work, like brush hogging.

I have tested the suction line for leaks, replaced the pump, but still it comes down to changing the oil and cleaning the screen to make it work. Because of all the oil changes, I was using a cheaper tractor hydraulic oil and in the trouble-shooting guide it said that my symptoms could be caused by using the wrong oil. I thought maybe the cheap stuff was getting hot and loosing whatever it takes to run the tractor hydraulics. So I changed to some Mobil oil with the right numbers for my tractor and cleaned the screen, but this time the hydraulic system still doesn't work.

Testing the pressure in various places gave me some conflicting results. I got into the guts of it once, but could detect nothing wrong. The o-rings looked good and there were no broken springs. Recently, I tried replacing the 3-point piston seal---no help.

 

[JC-jetro]

I have a Ford 1700. Besides the 3-point, it has power steering and a front loader which all run on the same hydraulic system. Eventually, the hydraulic system begins to make noise at the pump mostly and then slowly over time and use the hydraulic system quits altogether--no power steering, no lift on the 3-point, and no lift on the loader. Usually, by changing the hydraulic oil and cleaning the screen (not that dirty) everything would be good as new. Usually this takes several months to a couple years to run it's cycle. What seems to set it off is some serious pto work, like brush hogging.

I have tested the suction line for leaks, replaced the pump, but still it comes down to changing the oil and cleaning the screen to make it work. Because of all the oil changes, I was using a cheaper tractor hydraulic oil and in the trouble-shooting guide it said that my symptoms could be caused by using the wrong oil. I thought maybe the cheap stuff was getting hot and loosing whatever it takes to run the tractor hydraulics. So I changed to some Mobil oil with the right numbers for my tractor and cleaned the screen, but this time the hydraulic system still doesn't work.

Testing the pressure in various places gave me some conflicting results. I got into the guts of it once, but could detect nothing wrong. The o-rings looked good and there were no broken springs. Recently, I tried replacing the 3-point piston seal---no help.

Good explanation. Hyd fluid like you said is important. I have changed the hyd fluid 3 times since I owned the tractor. I think the very first time I changed the oil it was the first time for the tractor. Then the lift piston seal was gone and had much buildup in the screen. As soon as that was done tractor worked fine but pump started acting up due to shaft seal sucking air or leaked in the timing cover that I could not tell. I then overhauled the pump using new shaft seal and new set of pump seal and gaskets. The original seals did not look bad and there was no damage to the pump bushing , gears and mating surfaces. Ever since (at least 12 years) teh hyd system worked like a champ. Second time I change was because had to store the tractor under a tarp during my house constructions and it took moisture and condensation. First time I used NH oil as I had a dealer near by. Later on the dealer left and my best source was Tractor supply and I used their premium universal (Mysticc and then Traveler) that met Ford 134 spec and never has any issues, none. The only relevance i can see on using heavy PTO is the extra heavy load it put on engine and things gettingn hot including the hyd fluid. Your PTO is entirely mechanical. If you had hydro-static transmission then Oil would be very critical. Now oil loses viscosity as it heats up and hyd pump may not have the same pumping efficiency. I would concentrate on the pump first. Did you do the overhaul or just bought a pump? did you take the banjo of the discharge of the hyd pump to see if the pump is moving fluid? did you check the pressure relief and by pass? it is where you would have a hyd block since having loader. Let's just break it down to component starting from simplest by checking relief and then pump. Instead of taking the banjo off on pump discharge you can remove the pressure relief cap, spring and lil conical poppet and then start the tractor to see if you have oil shooting out. Need to have a helper , 5 gallon bucket and some plastic to divert the oil in to a bucket to avoid a big mess. That's where I would start. Let us know and we will get to the bottom of it.

 

[Marinemammal]

It was a new pump and it has about 60 hours on it. I did not take the banjo off the pump and run it. But it did have pressure as described below. I did have that relief valve under the seat apart and everything looked good.

The hydraulic oil was changed and the screen cleaned in May 2018. The oil was milky, but changing it fixed the hydraulic system. However, the hydraulics quit again in December 2018 after about 45 hours--the oil was milky and changing it fixed the hydraulics. It quit again just recently after about 60 hours. The oil was not milky, but it was dark--much darker than the new oil. This time changing the oil didn't help. This has been the pattern, but it would always be fixed after changing the oil, until now.

I have attached a couple of photos of the tractor hydraulic lines. Lines 1 and 2 are return lines from the power steering and the front loader. Line 3 is a pressure line that feeds a block that does some mysterious stuff and sends pressurized oil to the loader (line 4) and the power steering (line 5). That block seems to prioritize oil going to the loader and the steering with more going to the loader. The last time I put a gauge on line 3 (before changing the 3-point piston seal) it was reading about 1500 psi. My manual recommended testing the pressure at the plug next to line 3. I got zero there.

After the problem is resolved, I am considering putting a normal "T" instead of that block that separates the pressurized oil to the loader and steering because it runs the oil through some small holes that would tend to heat it up.

I didn't get time to do the testing you recommended today, but will try to make time tomorrow. Thanks for your help.

 

[JC-jetro]

Nice, I have not seen this hyd plumbing before but it is interesting. Basically, you got one pressure line going to a diverter block on for loader and one for power steering. Probably power steering has a smaller orifice to prioritize more flow to the loader. Then you got two return lines that go to main hyd block to return to tank.
1- The pics below show where the main pressure relief block is before anything else is served such as 3 point, loader or Power steering. In the pressure relief is where there is spring ,port and a poppet to maintain factory adjusted pressure(adjustable). if pressure is increased beyond the set point the poppet will lift and return the fluid to the diffy. If that happens it should chatter. if there is something keeping the port open then you may not be making adequate flow and pressure. Need to make sure nothing is broken and it is clean. That is where I suggested to check for pump flow.

This is where you can test if you have pressure and flow at the 3 point. Factory spec at 2450 rpm is about 2100 psi if my memory serves me correctly.

This is a check valve and ball to release shock loading to the 3 point to protect the 3 point piston seal. Let's say you have a heavy implement hanging in the back and you are going over a rough terrain, that shock load will add to the pressure trapped and can be quite high. Now you need just to make sure springs are not busted and balls are nice and round. Highly unlikely but you can bleed all the pressure and flow to the diffy. just something to check.

 

[JC-jetro]

Just noticed the quality of oil issue. Below is how mine looked with a tarp on the tractor being outside for 6 months during my house construction. That caused my 3 point to work erratically. The bottom of diffy is the reservoir of the hyd fluid. It is the area of low velocity of fluid and things collect. I made vacuum suction bottle (same concept as medical vauum used in surgery and dentistry). I was able to clean the floor of the diffy from where the screen is removed. You will be amazed how much crap gets collected there. Obviously , you do not use a soiled diaper on a baby,funny comparison but you don;t want to dilute brand new oil with all the contaminant. Make something like that and clean the bottom of diffy without getting your shop vac soiled.

JC,

Hole is for pressure regulation so the gallon jar would not collapse, getting sucked in.

 

[Marinemammal]

I had done some of that work of cleaning out the oil reservoir last oil change, and maybe that was the reason that this last oil change did not show the milky oil like in the past. I never was sure whether it was milky do to air or water. I did put some of the milky oil in a jar and it never separated--after years of sitting on a shelf.

I removed the pressure regulator insides and we were getting oil out there--maybe 2 quarts in 30 seconds and not really squirting out. I reassembled that and checked the pressure where you indicated (your photo with the gauge) and got zero psi--even when adjusting the pressure regulator in and out. This latest picture I attached is of the block between the pressure regulator and the side cover. The lower fitting in the block is #3 in the previous photo--a pressure line that goes to that block on the other side which divides into the steering and the loader. Checking the pressure there increases the hydraulic noise. The pressure builds to about 1500 psi and then releases down to below 1000 before building back up again. Seems odd to have pressure there and still no steering or loader function.

The upper fitting in that block is #1--a return line from the loader valve. The lowest hose in the photo is a return line from the steering that plugs right into the side cover.

I didn't get this tractor new, but in the early 1980s. I think that the power steering was added later by the previous owner.