Ilikeurtractor
Veteran Member
- Joined
- May 16, 2011
- Messages
- 1,070
- Tractor
- Iseki TX1300F/TX1500/ TX2160F/TS2220F/ Satoh S370D/S373D
Today I moved the remote hydraulics off my donor machine to the TX1300F. I marked all the hose connections so they would go back the same way they came off the other tractor. After everything was together enough to test it I bled the lines of air and that seemed to go ok. Then I discovered that once the lines had the quick-connects on them (which effectively made the lines "dead-headed"), when I would operate the control valve it would kill the engine. Clearly something was not correct. Since I've had other hydraulic problems, mainly with the 3-pt not going down on the donor, I concluded there must have been something seized-up in the control valve, primarily in the relief valve circuit.
I took apart the relief valve portion of the control valve and although it came apart ok, I thought the spring was maybe too strong (someone has changed it???) so I ran to the hardware store and found some weaker ones. To my dismay the weaker spring made no difference so I left the spring out altogether and it still stalled the engine when I operated any of the levers. Next I took the relief valve nozzle out and then it didn't stall the engine but also I could tell it wouldn't build any pressure. Now I was really confused! :shocked: The relief valve uses a spring to hold the valve against its seat and with no spring it couldn't possibly hold back any pressure since it would come out easily with a pair of needle-nose pliers when I took it apart.
After stepping away from the job and trying to figure out what the heck was going on it suddenly dawned on me I probably had the pressure and return lines swapped and, sure enough, that's what it was. Now I don't know if somehow I marked the lines wrong or it was installed that way the donor machine. The control valve was taken down from the fender mount when I received the tractor but still attached to the lines so there is a possibility someone prior was working on it and caused the mix-up.
So by having the pressure and return lines swapped, the relief valve could not see the pressure from the side it's suppose to, and in effect, I was causing it to close *harder* against its seat from being pressured from the return side. That's why it didn't make any difference when I took the spring out altogether.
Anyway, I'm posting this so if anyone runs across the same situation maybe this can help keep at least the supply and return lines straight because it definitely makes a difference. The control valve is a "Cessna 300922-3OC" the best I can tell. I have difficulty determining if the model has letters or numbers but I found reference to what I have listed on the internet.
Incidentally, I also confirmed the pumps on these tractors have no internal relief valve otherwise I probably wouldn't have even noticed the problem. Thankfully I wasn't running the engine over about 900 rpm when doing this and it would stall the engine rather than break something which is actually pretty surprising. I thought about revving it up a couple times just to "see if I could break whatever was sticking free" but obviously that would have been a bad idea.
I took apart the relief valve portion of the control valve and although it came apart ok, I thought the spring was maybe too strong (someone has changed it???) so I ran to the hardware store and found some weaker ones. To my dismay the weaker spring made no difference so I left the spring out altogether and it still stalled the engine when I operated any of the levers. Next I took the relief valve nozzle out and then it didn't stall the engine but also I could tell it wouldn't build any pressure. Now I was really confused! :shocked: The relief valve uses a spring to hold the valve against its seat and with no spring it couldn't possibly hold back any pressure since it would come out easily with a pair of needle-nose pliers when I took it apart.
After stepping away from the job and trying to figure out what the heck was going on it suddenly dawned on me I probably had the pressure and return lines swapped and, sure enough, that's what it was. Now I don't know if somehow I marked the lines wrong or it was installed that way the donor machine. The control valve was taken down from the fender mount when I received the tractor but still attached to the lines so there is a possibility someone prior was working on it and caused the mix-up.
So by having the pressure and return lines swapped, the relief valve could not see the pressure from the side it's suppose to, and in effect, I was causing it to close *harder* against its seat from being pressured from the return side. That's why it didn't make any difference when I took the spring out altogether.
Anyway, I'm posting this so if anyone runs across the same situation maybe this can help keep at least the supply and return lines straight because it definitely makes a difference. The control valve is a "Cessna 300922-3OC" the best I can tell. I have difficulty determining if the model has letters or numbers but I found reference to what I have listed on the internet.
Incidentally, I also confirmed the pumps on these tractors have no internal relief valve otherwise I probably wouldn't have even noticed the problem. Thankfully I wasn't running the engine over about 900 rpm when doing this and it would stall the engine rather than break something which is actually pretty surprising. I thought about revving it up a couple times just to "see if I could break whatever was sticking free" but obviously that would have been a bad idea.
