Steering logic.

[ponytug]

Most of us don't have soil like that...

You fellers talk of tamping a fence post,
don't think I ever did that, I dig a hole by what ever means available, auger or shovel, then drop in the post, add a 5 gallon pail of water give er take, then kick in the previously removed dirt, wiggle the post some to distribute the dirt maybe poke a branch or stick in there to make a good sloppy mess and walk away.
Tomorrow it will be as hard as if yall used cement. been doing it that way for 50+ years.

 

[MossRoad]

You fellers talk of tamping a fence post,
don't think I ever did that, I dig a hole by what ever means available, auger or shovel, then drop in the post, add a 5 gallon pail of water give er take, then kick in the previously removed dirt, wiggle the post some to distribute the dirt maybe poke a branch or stick in there to make a good sloppy mess and walk away.
Tomorrow it will be as hard as if yall used cement. been doing it that way for 50+ years.

I see this is your first post. Welcome to TBN!

 

[ol'George]

Thank you!!
I thought I would try to give back a little after all the "taking" of knowlege I have done here on TBN.

 

[J_J]

ol'George ,

On the subject of post. Maybe you are young or old, but whatever the case, old people don't like to physically work more than they have to, and therefore, when there is an easier way of doing things, they will. I don't particular like to dig holes, but have dug a few in the past. Of course you can dig or auger a hole, but the post pounder, and the vibratory units will sink them in short time. If setting post is your business, time is money, and whatever will do it the fastest is the way to go. No backfilling, no nothing, just go to the next one. Although they are expensive, they will pay off in the long run

 

[ol'George]

posts.--
well lets just say I'm old enough for social security Ha,LOL
and I've sunk a few holes
I have a 12" Hyd. auger I built to put on my hoe, in place of the bucket.
in normal ground, it takes longer to position it, then does to screw a hole in the ground, I timed it once, 4 seconds, now that was in clay, not rock
if I want to just drive in steel posts, I use the fel bucket to push them in,
or the hoe bucket, but when I'm sinking utility poles, I use the auger. then do the water trick.
In my younger days I didn't have power equipment,
I had more time than money & I did everything by hand.
but now it is just a hobby keeping me busy so the devil don't take me.

 

[ol'George]

I'm not trying to hyjack your discussion & I'm not familar with your machines at all, but thinking
does the steering circuit have a fixed priority valve for the steering with relief,
and the excess go to the lift, if so
I'm just wondering maybe a high hour machine might have excess by pass on the spool in the priority valve giving some lost gpm's to tank?.---
or the priority orfice is allowing more Gpm's than needed to the steering circuit and the steering relief is dumping those Gpm's it to tank when turning the gear to lock, starving the lift circuit.
forgive me if I mis understand the lengthy discussion. just trying to learn
are you using a ross steering valve?(pump they call it) .

 

[J_J]

Yes, the steering does have a priority valve. Only the fluid from the steering cylinders goes back to tank. When you are not steering, or steering slightly, the rest of the fluid flows through the steering valve and on to the lift and tilt valve, and then back to tank. So even if the steering was bypassing, the fluid would go downstream. If the priority valve was not working, the cylinders would creep. The steering and lift on my PT-1445, is powered by a .194 cu in pump, providing 1.5 - 3 GPM, driven off the fan belt. This gives me the ability to lift about 1200 lbs.

A hard turn either way, will use just about all the fluid and the lift and tilt will barely move. So sometimes you have to coordinate total steering verses something you are trying to lift or tilt.

That pump is just one of three that the PT uses.

 

[ol'George]

ok, that is what I was thinking. they been doing it that way for many years
I looked up a pix your unit so I now know what you have.
I'm thinking the other pumps are for the hydro units??
just the rambling of an old man, but that pump is on the small side, to do both jobs together, as you have found.
I'm sure you have it in your mind what you want to do by now, if anything.
If it were me I would entertain the idea of going a bit larger on the pump,-- or divorce the steering, adding a separate dedicated pump, possibly of the auto industry design.
They are a dime a dozen & easy to obtain @ salvage
they put out #900-1400 .
Although I don't know what is required for your articulating cyl's I'm assuming you have 1,-- or 2 in a cross over design, either way they require about the same flow. unless I forgot something.
the other side of the coin is you already have lotsa pumps in there!!
---trying to think like a liability scared safety engineer, they don't want the operator turning and lifting @ the same time.
Geo.

 

[ol'George]

Moving along so as to keep the posts small.
I understood a priority valve to split the flow into 2 distinct flows:
One metered either through fixed or adjustable orifice,
the other is excess flow. to do other work or dumped--RTT

so the steering valve gets for example, a dedicated 1 gpm.
( we understand there is a relief valve in that circuit with RTT on excess pressure rise)
it is directed through the steering valve to do work (turn cyl's) or it is RTT.

The excess flow goes to a spool valve to do other work,-- in this example tilt & lift
if the pumps output is 3 gpm's, 2 gpm's are left to do this other work.
( again just for example)

If the priority valve is leaking somewhere it will not cause any cyl's to creep as they are down stream from the tilt/raise spools ( and usually they have load check valves)
Disclaimer:
I'm not always right and by discussion I learn.

 

[J_J]

My PT's pumps are sized for the HP available. I could go a little larger on the lift pump, but not much. The pump size is also related to the safe operation of the machine, meaning that although the lift cylinders have more potential, is does no good if the back end comes off the ground. Actually larger cylinders will increase the lifting power, but again, there is a lift weight ratio that has to be considered.