Yet another Ford 1700 with hydraulic issues...

[teachag295]

I put the pump back on today and got it seemingly primed. The hydraulics seemed even weaker than before. I would have to lift the hydraulic arms for the Piston to move and then they would stay up and lifted position. I pulled the gauge off of the test port and the oil barely trickled out at half throttle. It also was very foamy which seems to indicate to me that either it is not fully primed and or air is getting sucked in somewhere.

Thinking about this logically, the system was working fine before I changed the fluid and changed the strainer which had a hole ripped in the screen. I did not touch anything on the top end. This makes me think that the problem is more likely to be on the supply side of the system rather than the relief valves. I have checked the o-rings more than once on the suction line. As much as I hate to say it, I'm thinking that maybe I should pull the strainer and double check it to make sure it is not somehow clogged up. I pulled the suction line off of the strainer and looked at it from the inside but I could not see the screen part. I also thought about putting flex seal on the outside of all of the fittings. This would not be a long-term solution but when we were trying to troubleshoot hydraulics back in the day we would smear grease over fittings to try to pinpoint an elusive leak. This would be a similar concept. I feel like I either did not get a good seal on something on the suction side, somehow clogged up the strainer, or damage something else on that side. I also wonder if the pump even though it looks good is weak and possibly the previous owner tore a hole in the strainer to allow more flow. With no metal in the case or any other sign of damage in there, I have no idea how the strainer would get a chunk of the screen ripped open unless it was done intentionally. Also, having that opening in the screen would mean the pump would be subject to larger abrasive material.

Is my logic off base?

 

[JC-jetro]

I put the pump back on today and got it seemingly primed. The hydraulics seemed even weaker than before. I would have to lift the hydraulic arms for the Piston to move and then they would stay up and lifted position. I pulled the gauge off of the test port and the oil barely trickled out at half throttle. It also was very foamy which seems to indicate to me that either it is not fully primed and or air is getting sucked in somewhere.

There is a check ball and spring(check valve, on way flow) in the lift piston head. That would trap oil back in the lift cylinder. The only way 3 point arms drops is either check valve is not holding, lift piston seal is leaking or installed incorrectly or if lift spool valve is leaking.

Thinking about this logically, the system was working fine before I changed the fluid and changed the strainer which had a hole ripped in the screen.

Hole, if any in the strainer will only help with prime as there is less suction pressure loss. Saying that it can allow crud from the bottom of diffy floor to enter the suction pipe and in to the pump. on mine, I shop vacuumed the floor of diffy with a shop vac and with the strainer removed. I was able to get at least 2 quarts of oat meal looking crap from bottom of diffy collecting over perhaps 25 years. I would drain the hyd fluid in clean bucket and inspect the strainer and clean the floor of the diffy for sludge. since the oil is clean then straining it thru a coffee filter should clean it up. it will be slow. I will fix the hole in the strainer. if you decide to do so, take pics and post. There might be tell tale signs.

I did not touch anything on the top end. This makes me think that the problem is more likely to be on the supply side of the system rather than the relief valves. \

supply and relief are both on the same part of the system. There is particularly nothing significant with the pipe unless it has an obstruction. The issue is, like I said before the relief valve spring is what causes the system pressure. It can also divert the flow to diffy without going to 3-point if the poppet valve is stuck open due to crud collecting there. The relief valve need to be opened and inspected.

e I should pull the strainer and double check it to make sure it is not somehow clogged up. I pulled the suction line off of the strainer and looked at it from the inside but I could not see the screen part.

yup, agreed.

I also thought about putting flex seal on the outside of all of the fittings. This would not be a long-term solution but when we were trying to troubleshoot hydraulics back in the day we would smear grease over fittings to try to pinpoint an elusive leak. This would be a similar concept.

Suction line is under suction when the pump is running, it can only suck air in when the pimp is on giving some clue to foaming. it can leak a bit of oil while the tractor is parked if the hole is large enough or the flat gasket on the strainer is not sealing tight. I , personally would clean u the joint , smear a thin layer of RTV blue on the gasket, let it skin and dry out a bit and put it back together.

I feel like I either did not get a good seal on something on the suction side, somehow clogged up the strainer, or damage something else on that side

yup , like I suggested on previous paragraph

. I also wonder if the pump even though it looks good is weak and possibly the previous owner tore a hole in the strainer to allow more flow.

pump can be weak or seal due to slight damage to nylon backer is not sealing well to make pressure. Do you have any pic of the gears? pump is expensive to source. I will be attempting overhaul rather buying a new one. I still don't think we're where we should logically think of pump replacement yet.
pics

With no metal in the case or any other sign of damage in there, I have no idea how the strainer would get a chunk of the screen ripped open unless it was done intentionally. Also, having that opening in the screen would mean the pump would be subject to larger abrasive material.

pump suction cannot poke a hole in the screen. I think it was done intentionally. Any piece of metal in the pump would have certainly left tell tale signs. The interior case of the pump does not support it. It looked smooth. Any damage on the gears?

Is my logic off base?

Logic is okay, but always is a mix bag. My concentration more is in the relief valve area. I simply take the outer nut off the relif valve, put a shop towel ove the hole, put a bucket underneath and the run the tractor. You shoud have good steady flow(not a lot of pressure). it is messy but at least you can tell if the pump appears to work.

 

[teachag295]

I am attaching pictures of my relief valve and check valve. I disassembled them again to make sure that they were put in correctly and all the seals looked good. They're not many o-rings or seals in them but those that are there look good to me. The only question I have is with the relief valve the parts manual does not show a groove in the valve poppet. See the picture where I am pointing to it with a pick. I am not sure if there is supposed to be a o-ring there but I do not think one would fit clearance wise. Also the plug at the end of the housing is solidly stuck in there. I did not try to pound it out but I'm not sure how free that is supposed to be. That will be the second picture I am pointing to with a pick. Before I started pulling things apart, I turned it on and opened up the port. The first video shows no flow. It took about 20 seconds for flow to start which can be seen in the second video. As you can see the fluid is very foamy. There is no water in it. When the phone settles it looks brand new.

This leaves me thinking that it may be time to pull the filter housing to make sure that there is a good seal there. If it is not that then it has to be the pump unless I'm missing something on the top end. The rebuild kit for the pump runs around $160 I believe I found a place that sells new aftermarket pumps for $300. In Europe they sell these pumps for around $130.

Also you are absolutely correct that the suction did not damage the screen. It was mechanical damage of some sort. I do not know if something got in there and tossed into it by the gears in the transmission or if someone did it. I suspect that it was something that was thrown by the transmission because the housing did not look like it had ever been removed when I pulled it off. I do not know if I still have it sitting around in my shop somewhere. It was about 4 years ago. I will have to look and see what I can find. If I can find it I will post pictures.

Ford 1700

Ford 1700

Here is the outside of the relief valve that I believe it's the newer style than yours.

 

[teachag295]

Quick update. I let the tractor run for about 45 minutes at roughly half throttle with the draft lever in the down position. I was hoping that if there was air in the system, it would give it a chance to flush itself out. I did not open up the port to see the condition of the fluid again but I still did not have hydraulic power. Also an answer to the question from your last post, the gears look fine with really no noticeable where on them.

 

[JC-jetro]

Good pictures. I did go to NH website and looked at parts breakdown for the relief device. It is exactly the same as the picture you have. Mine was pre-1979 and is adjustable as the pics show. Yours use shims to add pressure by increasing the spring stiffness. what is a bit curious is the groove as the the website does not show that and on your s it is there and machined. I can't explain why they machine a groove that serves no purpose. I am sure I can get a o-ring out of my HF , metric rubber o-ring assortment to fit one in there. like yours, the NH website shows plug #5 next to 1A or the housing. Did you see that plug #5? I don't see it in your picture there.

Your oil does not look good on the video, is it all foamy or just dirty? did you use right hyd oil,Ford 134?

All the lift cylinder head check balls look ok and I don;t thing there is any problem there.

If it were me, I would take one of the shims out and then fit an o-ring on the groove and give it a try. Now I have not done that but can't see harm doing it specially since you are meticulous in disassembling the parts and putting back together.

If you decide to re-visit the suction screen then I would suggest cleaning the floor of diffy like the pic below suggests. The shop vac is connected to the any plastic bottle and it collects the crud without messing up your shop vac. do put a small hole in the handle so the vacuum would not collapse the bottle.

At the end hyd pump might be tired and needs replacement but you need to exhaust all options before going to last resort. if issue lies somewhere else then the pump might not be the cure, it is $$$ and not returnable. Let's just keep digging at it and hopefully we can find the problem.

Let's work on suction screen, cleaning the diffy and making sure you have the right oil.




PS. I just re-read your post. you addressed the question I had on the plug #5. It looks to me that the pump pressure should work against the plug to lift the popper against the spring. it might be e tight fit between plug and the housing but has to able to move. My version of it seems to be a bit easier to see how it works. Hyd pump does have an internal bypass to help lubricating gear shaft against the bushing. I am wondering if that causes the cavitation and foaming. Cavitation almost always happen on the suction side of the pump though. I am stomped a bit but keep trying like I suggested above. I kick myself for not buying extra pump overhaul kit and lift piston seal since it was cheap when I bought them.

PS2. is block #5 is the one you pointed on picture before the relief diagram? is there another plug on the right side of the relief device? wondering what block #5 purpose is. do you think the popper just rests against the block, flat surface to flat surface ? 3 holes that you see on top hat cover of the diffy is one pressure from pump, second is relief to the diffy and the 3rd is pressure to lift spool valve.

 

[teachag295]

The bulk of the oil and there is 134 fluid I got from the local New Holland dealership. It was 4 years ago and I do not have the original bucket and jug I bought but I am positive it was Ford 134. I did top it the other day with about 3/4 of a gallon of Tractor Supply UTF which says it is Ford 134 compatible. Either way we were having the problem before the tractor supply fluid.

I guess it could not hurt you try to throw an o-ring on that part. It would be a 5-minute job are way better. I just was giving students something to do when they replaced the radiator and such. What would be the benefit of taking one of the shims out? Wouldn't that do the opposite and further lower the pressure?

The fluid is not dirty. When I first saw it come out like that I thought it had water in it because it almost looks that way but when it settles there's no water in it. It is just foam also when I drained it out there was no water in it. The phone indicates to me that air is getting into the system somewhere I would think. I really wish there was a way for me to put a game right on the hard pressure discharge line before the relief valve or right on the side of the pump to test it. I may check to see what kind of thread the banjo bolt is and see if I can get a adapter too put the gauge right on the side of the pump. That would be very telling.

I like your suction bottle idea. I have an old shop vac that I just sacrificed for that purpose. I do not remember how well I cleaned the bottom of the differential. When I deal with something as dirty as this was I usually scrub it out with a little bit of diesel and really clean it and then flush it with some extra hydraulic fluid or oil depending on the application before I put the final fluid in but I do not remember if I did that in this case. I am kind of thinking I didn't because I was worried about whether or not I could get all of the diesel residue out and I didn't know what type of seals were in there that I could not see.

That is the plug I'm talking about. As you can see there is some don't get looks like between the assembly the plug is in and the plug that seems to be jamming it in there. It appears at the end of that piston looking part of the puppet rests against the plug which risks against the end of the cylindrical space that the assembly goes into. I'm not sure the purpose of the plug. Maybe I will try to press it out. I am not really tried beyond trying to push it out with a pick.

I am busy with FFA tri-tip dinner fundraiser today (life of an AG teacher) but I will drain it the fluid again and see where that takes us tomorrow most likely. Also for what it's worth, yesterday just to double check to make sure the pump was primed, I cracked the banjo bolt at the pump on the suction side and used a couple PSI of air pressure in the case until oil started coming out at the banjo bowl then closed the banjo bolt. I really appreciate all of your help. It is good to have someone to brainstorm with it understands what you're working with.

 

[JC-jetro]

The bulk of the oil and there is 134 fluid I got from the local New Holland dealership. It was 4 years ago and I do not have the original bucket and jug I bought but I am positive it was Ford 134. I did top it the other day with about 3/4 of a gallon of Tractor Supply UTF which says it is Ford 134 compatible. Either way we were having the problem before the tractor supply fluid.

I guess it could not hurt you try to throw an o-ring on that part. It would be a 5-minute job are way better. I just was giving students something to do when they replaced the radiator and such. What would be the benefit of taking one of the shims out? Wouldn't that do the opposite and further lower the pressure?

The fluid is not dirty. When I first saw it come out like that I thought it had water in it because it almost looks that way but when it settles there's no water in it. It is just foam also when I drained it out there was no water in it. The phone indicates to me that air is getting into the system somewhere I would think. I really wish there was a way for me to put a game right on the hard pressure discharge line before the relief valve or right on the side of the pump to test it. I may check to see what kind of thread the banjo bolt is and see if I can get a adapter too put the gauge right on the side of the pump. That would be very telling.

It is just odd, if it sucked air externally from the strainer housing where it connect to the banjo , then it shoud also seep out some when the tractor is off. Like i said it on my old thread, my pump selas and backer looked good then but my problem eneded being shaft seal. The thing is if it is indeed the shaft seal, it will leak out or suck air in inside the timing chain cover and the oil will go back to crankcase. I think it is quite difficult to tell few spoons of hyd oil in the crankcase oil. if you decide to do the pump overhaul do make sure to check the shaft seal. I have hard time to see the nylon seal that is chewed a bit can cayuse your problem. I think that was original when they put the pump together and had teh backet a bit misaligned.

I like your suction bottle idea. I have an old shop vac that I just sacrificed for that purpose. I do not remember how well I cleaned the bottom of the differential. When I deal with something as dirty as this was I usually scrub it out with a little bit of diesel and really clean it and then flush it with some extra hydraulic fluid or oil depending on the application before I put the final fluid in but I do not remember if I did that in this case. I am kind of thinking I didn't because I was worried about whether or not I could get all of the diesel residue out and I didn't know what type of seals were in there that I could not see.

funny story, I opened up the drain on the bottom of the diffy to drain the oil when I did it first time more than 15 years ago. Nothing came out. Opened up the drain at the transmission and it started draining. Took a thin long screwdriver and shoved it in the diffy drain and a bit of oil cam out. Then I made a hook with some stiff wire , shoved it in the hole and pulled it out. I kid you not , I pulled aomethng that lookd like a dead desiccated rat from the hole. That was what caused me to look inside and trey to clean the diffy. All crud builds there as it is area of low velocity and not much flow. I took two quarts of muck looking like thick oat meal. I only have done it once. Second oil change was what I pictured and the tractor was outside under the tarp while I was building my house on the farm and it picked up all that condensation in 9 months.

That is the plug I'm talking about. As you can see there is some don't get looks like between the assembly the plug is in and the plug that seems to be jamming it in there. It appears at the end of that piston looking part of the puppet rests against the plug which risks against the end of the cylindrical space that the assembly goes into. I'm not sure the purpose of the plug. Maybe I will try to press it out. I am not really tried beyond trying to push it out with a pick.

I think that plug is harderend strike surface for the poppet valve. When you dead head the pump by raising the 3 point to the highest point then the releif chatters and lets you know to lower the 3 point. That sound is caused by the poppet hitting that surface. On mine looks a bot different and conical shape poppet on mine hits the hardened seat and chatters.

I am busy with FFA tri-tip dinner fundraiser today (life of an AG teacher) but I will drain it the fluid again and see where that takes us tomorrow most likely. Also for what it's worth, yesterday just to double check to make sure the pump was primed, I cracked the banjo bolt at the pump on the suction side and used a couple PSI of air pressure in the case until oil started coming out at the banjo bowl then closed the banjo bolt. I really appreciate all of your help. It is good to have someone to brainstorm with it understands what you're working with.

Good job on FFA dinner, it is for the good cause. I am confident you will figure it out before too long. The key is to do the correct repair at the right cost. I personally would not buy a brand new pump that is most likely is China made and not as good as OEM. I would change just the consumable and wear items. Do check the shaft seal as it was my problem. I did put the new pump seal only because I had it and could do it.

 

[teachag295]

My oil originally was nowhere near as gunky as yours. It basically just had moisture in it. I'm still baffled as to why it would have worked fine until I changed the fluids and the filter. I will check the filter but as I think about it logically you are absolutely right that it should be leaking if there is a air leak on the suction line. Also, I checked and replaced the o-rings on the banjo bolts on the section side. Is it was leaking where the filter/strainer attaches to the side of the case, it would not suck air from there because that would be independent of the basket. I'm really thinking about just popping the top off of the case between the seat and the shifters to inspect down there.

There is a tapered surface on the puppet as well with mine so I am not 100% sure how that works. I still may see if I can free that plug up.

I am hoping at this point that the problem is the shaft seal. I feel like I am running out of other options. I am trying to visualize the path of the oil through pump to see what side the shaft seal would affect.

You are probably right about the OEM pump being better quality. It looks good inside so I may just like the bullet and do the seals if I cannot find anything section side that is problematic.

The correct repair for the correct price is the key. I'm getting tired of throwing money in nickel and dime quantities at this issue. 200 tri-tip cooked... Back to the grill...

 

[JC-jetro]

My oil originally was nowhere near as gunky as yours. It basically just had moisture in it. I'm still baffled as to why it would have worked fine until I changed the fluids and the filter. I will check the filter but as I think about it logically you are absolutely right that it should be leaking if there is a air leak on the suction line. Also, I checked and replaced the o-rings on the banjo bolts on the section side. Is it was leaking where the filter/strainer attaches to the side of the case, it would not suck air from there because that would be independent of the basket. I'm really thinking about just popping the top off of the case between the seat and the shifters to inspect down there.

If you are talking the top differential case where the seat is then on this model you do not need to do that for inspection of the seal of lift piston or rock shaft. They can be done from the front taking off the lift cylinder head.

There is a tapered surface on the puppet as well with mine so I am not 100% sure how that works. I still may see if I can free that plug up.

Tapered surface (conical in my case) mates with the seat to resist the flow with spring in the back pushing valve away from the seat. Pressure developed by pump flow against the tapered poppet lifts it up to maintain pressure that the spring stiffness causes. it is sort of safety pop off , lets say on a boiler. It opens up to protect boiler or pump in this case.

I am hoping at this point that the problem is the shaft seal. I feel like I am running out of other options. I am trying to visualize the path of the oil through pump to see what side the shaft seal would affect.

simple representation of how a gear pump works. gear pump is one type of positive displacement pump.

You are probably right about the OEM pump being better quality. It looks good inside so I may just like the bullet and do the seals if I cannot find anything section side that is problematic.

at this point it is the logical thing to do.

The correct repair for the correct price is the key. I'm getting tired of throwing money in nickel and dime quantities at this issue. 200 tri-tip cooked... Back to the grill..

Looks good on the grill. Bon appetito!! better progress on that front!

 

[teachag295]

I already had the cylinder out and replaced the piston seal. I'm talking about the horizontal plate right in front of that that would be between your knees. I'm thinking that would give me a view of the strainer / filter.

Thank you. I understand the concept of how a gear pump works but I was trying to figure out if there would be something or pressure against the shaft seal.

I will keep you posted.