Steering logic.

[J_J]

Are you saying that there is a fixed orfice in the valve that only allows a certain flow to go to the steering cylinders? I am thinking that the more you turn, the valve opens more, and if you turn all the way to one side, you decrease the fluid going to the lift cylinders. In a partial turn, some fluid gets by. Is this correct?

 

[J_J]

While steering, there is only a little lift. When I stop steering, I have full lift.

 

[BobRip]

I just drove my 422 to test this. When steering (4 in bucket installed and empty) I can easily raise and lower the bucket and tilt it. If I hit the lock at the end of steering then the tilt becomes real slow. I think you have a mechanical problem with some part, not a design issue. I suggest you call PT and describe the problem to them.

Bob Rip

 

[J_J]

My 1445 is an early 90's. After searching the web, I came across an article about hydraulic and safety, so maybe it is the law. I think my 1445 is working like it is supposed to. Steering has priority, and does stop most of my lift. I just don't like it that way. An analogy might be, when you are using a backhoe, and you want to swing the boom and uncurl the bucket at the same time.

 

[BobRip]

Your machine may operate differently from my 422 so it's hard to tell. I would still discuss this with PT people.
OK, enough said.

Bob Rip

 

[Spiffy]

Blackwell, good to see you! I presume you still have a 24XX.

Can't let these (1)4XX guys have all the fun. /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif

 

[Spiffy]

<font color="blue"> (and I am not an expert on hydraulics, but I am one on electricity) </font>

/forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif

j j [caps intentially incorrect], I'm afraid you won't be able to communicate with Bob. He thinks you're imaginary. Of course, that could be j*j in which case you are real, but negative. /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif

 

[Spiffy]

Ok, assuming nothing wrong with JJ's machine and also that it is plumbed similar to newer models:

Then I'm thinking he may get away with putting a solenoid between the parallel connection he proposed [per Blackwells statement saying [I think he's saying] the ends of the steering are "deadheaded"; this does correllate to what we seem to be experiencing].

This would essentially then bypass the steering (yes, parrellel, but like electricity it will find the path of least resisitance or the combination thereof) at deadhead, and split in varying configurations depending upon loads at less than full steering. Only activated when he pushes a button on the joy stick (or where-ever) it shouldn't adversely affect any operation. /forums/images/graemlins/smile.gif

This make sense? Am I right, potentially right, or way off?

 

[toy]

I know Im not a hydraulic expert by no means but this is just how I think that it works. First of all the pump puts out a constant volum of oil and it needs somewhere to go. The oil goes over to the releif valve. There are two hoses coming out of it. one has a spring valve set to a designated pressure so that the oil can't flow that way unless the designated pressure is reached and in that case the oil could flow through that hose and back to tank. But there is another hose and at the releif valve there is no restriction of the oil flow at that point so the oil will flow through it to the steering valve. The oil enters on the left port so you have a pressure flow to there. now at that point the oil comes in to the steering valve and goes out the hose that goes to the valve bank which is an open center valve which allows the oil to flow back to the tank unrestriced. Now back at the steering valve I beleive there is a steep coarse threaded shaft. When you turn the steering wheel that opens up ports that allow the oil to go to the flow divider and then to the cylinders and then back to the flow divider and then back to the steering valve where it can go back to the tank. Now if you turn the steering valve to where it fully extends the cylinder and fully retracts the other steering cylinder there would be a full flow of oil going into the steering valve and with the sleeve pulled up as far as it can go I beleive it opens up an internal releif port that dumps back to tank and that is what robs the hydraulic fluid from the valve bank now when you back the steering valve back a little then it opens the oil flow back up to the valve bank. as you steer the steering valve it puts enough restriction in the inside of the port where the oil goes out to the valve bank to give you enough pressure to operate the steering cylinders. Sort of like a portioning valve that would divide the oil so much of the flow to go to one place to do that work and so much of the pressure oil going to another place to do that work. On scoops they have a valve like the quick attach valve pull it one way and it steers that way and push it the other way and it would steer in the other direction. and it had another valve to raise the bucket and extend the ram. I couldn't get a diagram to look at when I posted this but I hope I got it right.

 

[tracdoc]

oh boy..... now I really have a headache... wish I understood more about hydraulic valves and circuits /forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif