ford 1300 hydraulic problem

[JC-jetro]

yes that is the filter i changed. it had a new one in it replaced last year but when i took it out to check it the other day the rubber gasket on the back side of the filter didn"t look real good so i put a brand new one in. i started it back up last night after it sit all afternoon and the hyd worked strong i took it down in the field and cleaned a little ditch with the backhoe and it worked strong. called the guy i was doing the job for yesterday told him i would drive up at a slower speed and see if it would work then. drove at little better than walking speed and when i arrived backhoe and fel worked fine. every time i drive any distance i have this problem, this is the third time but it is the only time i have it. this is a standard transmission 4spd with 3spd auxillary do you think the gears churning in the oil could aerate it and make it hard to pump. also where the i think they call it a banjo fitting bolts to the diff under the seat is there a pickup pipe on the inside of the diff as it bolts fast to the diff very high up toward the seat, appreciate your help jc-jetro and also your input dabutcher. these are a super little tractor when they,re working right.

So #15 was the filter media you changed, Right? did you get the filter media from NH dealer? did yo compare the new filter with the one you just changed? You have a point that oils in churned up in the transmission some but not enough for it to foam. Your hyd system is pumping let say 8 gpm. That is a constant amount what ever you do not use for 3 point, backhoe or loader gets by passed to the diffy from the spool valve for 3 point or some other plumbed fitting directly back to diffy. Although transmission and diffy share a common sump agitation in the transmission does not directly cause the same in diffy as there is also a compartment between diffy and transmission that has pto input shaft and drive shaft. what I'm saying there diffy , middle compartment and transmission are linked together but the baffle in between keep any churning if any in transmission. Also remember your hyd pump is always running and the rpm is running is proportional to engine rpm and maybe at a bit height ground speed (on asphalt) causes the hyd pump to run a bit hotter needing to cool off a bit for a more efficient pumping.

I did not completely get the thing about banjo.. will you rephrase your question? are you able to take picture of the area you have question about? they alll hae the banjo fitting on fatter pipe to the hyd pump. the fat pump is always suction from diffy. the smaller dia pipe of the hyd pump banjo is the discharge pipe from the pump. that smaller dia pipe goes to a pressure relif device and the to lift spool valve.

when you checked the oil level, did you do it with backhoe or fel discharged or not. the reason say that is that I have a sight glass on my kubota, with the tractor on level ground and bucket down it shows full hys fluid. if I raise the loader and by filling the loader hys piston level goes down where an operator might think the oil is low. did you check the oil level with the dipstick and fel and backhoe down? I'm thinking may be you oil is actually low where you occasionally cavitation the hyd pump due to low oil.

See if you can add more findings leading to a solid clue.

JC,

 

[01hunter570]

yes that is the filter i replaced and it came from nh dealer. i was running on asphalt maybe you have a point about the pump getting warm as temp for the day was quite hot at the time. i also checked the hyd oil with the fel and backhoe on the ground and it was at the proper level. i don"t know how to put pictures on computer unfortunately i know about as much about the computer as i do hydraulics although i am learning a lot from you, thank you. i was also suprised to hear the smaller pipe is the discharge pipe from the pump. on a dump truck the largest hose is the return line. the smaller line is the one i was referring to as having a banjo fitting (round fitting on far end of small steel line with bolt thru the middle of it.) so the other line is the suction line? if i remember right it has a short rubber hose on it right close to the pump. by the way you have a point when i checked the oil when it wouldn"t work the oil looked clear not foamy or full of air thanks again for all your help. also checked oil by dipstick don"t have sight glass.

 

[JC-jetro]

yes that is the filter i replaced and it came from nh dealer. i was running on asphalt maybe you have a point about the pump getting warm as temp for the day was quite hot at the time. i also checked the hyd oil with the fel and backhoe on the ground and it was at the proper level. i don"t know how to put pictures on computer unfortunately i know about as much about the computer as i do hydraulics although i am learning a lot from you, thank you. i was also suprised to hear the smaller pipe is the discharge pipe from the pump. on a dump truck the largest hose is the return line. the smaller line is the one i was referring to as having a banjo fitting (round fitting on far end of small steel line with bolt thru the middle of it.) so the other line is the suction line? if i remember right it has a short rubber hose on it right close to the pump. by the way you have a point when i checked the oil when it wouldn"t work the oil looked clear not foamy or full of air thanks again for all your help. also checked oil by dipstick don"t have sight glass.

you are welcome. No issues with the pictures. i went to NH website and other than replaceable filter media in lieu of screen the rest is almost identical between 1700 and 1300. In general piping going to inlet of a pump hyd or otherwise is a bit larger. Th reason for it is to have pump volute flooded and have less change of pump cavitation specially in a open circuit pump (non-recirculating). This is true both for gear type pumps and variety of others that are not used in a tractor hyd system. There is always a lot of energy added to the fluid on the discharge side of the pump so pressure drop on smaller pipe is okay as the pipe is sized both for pressure drop and flow volume. You said on trucks the larger pipe is " return"... well that is also true in tractor. The larger inlet pipe to the suction side is actually return from reservoir to the pump. So in other words
supply side of the pump in discharge and return side is inlet to the pump. I'll add a few pics below here that in concept is almost identical with your rig.

#38 is discharge, outlet or supply pipe from the pump on the left side and on the right side banjo fitting it ties to a pressure regulating device and then to lift spool (aka , valve) for 3 point.

#25 id the larger dia pipe which can be called inlet, suction or return as you call it. banjo #26 is on the diffy and rubber hose #24 is the rubber hose to pump inlet.

Pump connection on top next to the filter is the inlet and outlet in on the bottom with smaller dia pipe.




Below I have a few pictures of my 1700 which conceptually is the same as yours.


Fords 1700: Larger dia pipe=suction, smaller dia= discharge.



Ford 1700: discharge pipe going to pressure regulator/relief device.



Ford 1700: suction banjo and fitting in diffy.



Keep watching it and take notes so we might get to the bottom of it.

JC,

 

[01hunter570]

talking with you has really opened my eyes to a lotof misconceptions i had. i always took it the return line returned the unused fluid to the tank and i never really worked on hydraulics before so i just assumed this. talking with you now it is all becoming clear to me. i was wondering how the small line that i thought was the suction got fluid as it goes into the top of the diff. i thought there must be an internas pipe going down into the diff. much like an oil pump in an engine has. looking at the tractor today it makes sense the large line is on the bottom of the diff. and runs to the bottom of the filter housing so the oil is filtered before it gets to the pump. the only thing i am still unsure of is where the diaper is. i take it is on the diff side of the large suction line but how it is hooked on there i can"t figure out. if i disconnect the suction line from the filter and take the bolt out of the banjo fitting on the diff end when i pull the bolt or pipe out will it be on the end of it? i know i have to drain the hydraulic fluid when i do this. thanks in advance for all the time and energy you have put in to this it's people like you who make these sites such as assett. keep up the good work jc-jetro!

 

[JC-jetro]

talking with you has really opened my eyes to a lotof misconceptions i had. i always took it the return line returned the unused fluid to the tank and i never really worked on hydraulics before so i just assumed this. talking with you now it is all becoming clear to me. i was wondering how the small line that i thought was the suction got fluid as it goes into the top of the diff. i thought there must be an internas pipe going down into the diff. much like an oil pump in an engine has. looking at the tractor today it makes sense the large line is on the bottom of the diff. and runs to the bottom of the filter housing so the oil is filtered before it gets to the pump. the only thing i am still unsure of is where the diaper is. i take it is on the diff side of the large suction line but how it is hooked on there i can"t figure out. if i disconnect the suction line from the filter and take the bolt out of the banjo fitting on the diff end when i pull the bolt or pipe out will it be on the end of it? i know i have to drain the hydraulic fluid when i do this. thanks in advance for all the time and energy you have put in to this it's people like you who make these sites such as assett. keep up the good work jc-jetro!

You're most welcome buddy, no one has ownership of knowledge and each and everyone of us havs a small chunk of it... and that's all. The fact is the more you learn the more you realize how much more there is to learn with no end.

Now, Please don't take me so literal, when I said "Diaper", I was just trying to use an analogy that made sense. I know you would not consider changing your motor oil without replacing an old and dirty oil filter or dirty diaper., would ya?

The oil from the small discharge pipe goes in to a spring loaded valve (like a check valve), the spring rating of the valve sets max hydraulic pressure in your system (around 2300 psi) before hyd system components gest damaged. After pressure regulation there might be a hyd block to take supply and return to let say loader and then the rest of the flow goes to a lift piston that does the 3 point lift. The valve that runs your 3 point fills the lift cylinder to where you set it and the rest of the oil (unused) gets splashed in to the diffy and gets collected there to be sucked up by the pump and pushed back to the system. Remember that the pump is gear pump and can not be dead headed (meaning you can't run the pump and valve off the flow internally or fully obstruct the flow). if so the pump will self destruct.

Like you suggested. If you take the banjo off next to diffy (after draining the whole system, save the oil for reuse in clean bucket) then you can get a shop vac or a collection vacuum Jar and I bet ya you get a bunch of crud with runny oatmeal consistency that get collected in the bottom. I bought my Ford 7 years ago and the hyd oil was never changed. Transmission dipstick showed clean oil but when I opened up the drain from the bottom of diffty nothing came out. I took a piece of bailing wire, made a hook on the end, shoved it thru the hole and pulled it out. I pulled a "dead rat" looking compilation of junk that covered the bottom, same as a plugged shower drain with hair and junk. That was the reason I ended up checking the screen and at the very least I collected 2 quart of junk without any metal shavingfrom the bottom of diffy ( that was the dirty diaper). After all of that I filled it with nice fresh Ford 134 and ever since had zero hydraulic issues.

crud like that occasionally might pass thru hyd system that is the same as "passing kidney stone" and it is a painful thing for the pump. Obviously I'm saying kidney stone as an example to simplify things.

Keep us posted and good luck. Don't hesitate to ask questions and I be glad to help if I can.

JC,