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Hydro steering Questions

3K views 16 replies 13 participants last post by  feva4u 
#1 ·
I'm trying to figure out what works and what doesn't right now.

Im currently running a 7.63 cu in open center load reactive orbital on my single ended 2 X 8" Ram. The truck darts all over the road while driving and kind of drifts right.

Any suggestions?


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#6 ·
I'm of very little help since I just bought a PSC kit. I didn't want to guess at all those fancy numbers. :sonicjay: I do know a little bit of toe in and a healthy amount of caster will help it handle much better, but as far as the bleed through inside the orbital while driving, I'm of no help.
 
#8 ·
"Load reactive (reversing)—The load reactive steering unit allows the steered wheels to return to the straight ahead position after the operator releases the steering wheel. This happens only if the steering geometry exerts a centering force on the steering cylinder. The cylinder ports are interconnected with the metering section so that the steering wheel follows the wheels back to center position. Reversing steering units should only be used in systems where the opposing cylinder chambers are of equal volume. DO NOT USE with a single unequal area/volume cylinder."
http://www.pirate4x4.com/tech/billavista/PR-Hydro_Steering/index2.html
 
#9 ·
Load reactive valves are a no go on single ended cylinders...i don't remember the specifics but there is a bunch of info out there on why. (I learned this after i had already installed my load reactive orbital on my single end system :fish:). Mine is ok on the street at slower speeds (prolly <45) as long as the tires are aired down (15psi or less).....if you air them up it acts like yours only not as severe from the sounds of it.
 
#10 ·
switch from a load reactive orbital to a standard or go to a double ended ram. The differences in volume and pressure required to move are causing your problem. Seeing as how retracting the cylinder would require more pressure than it would take to extend. More surface area to push against on the extend size, so more work with less effort. So your self centering orbital is putting a constant pressure to both lines to make it even out. One side needing less volume and more pressure than the other are causing your issues. Leaving alignment out of it.
 
#12 ·
Missed the part about single ended cylinder... I've read that they can get twitchy because the orbital moves a min fixed amount of fluid, sometimes causing you to fight back and forth. I might have dreamed that.

On mine I cranked the wheels together a quarter inch and made a big difference, but I need another hand with a tape measure to get it properly aligned.
 
#15 · (Edited)
Hell I will take a stab at this with some general stuff anyone who has ever worked on a tractor should know.

Jack the front your pile off the ground and shove some stands under the frame leaving the tires on.
Disconnect your ram linkage to your knuckle leaving the cross over bar connected and check for any play by rocking the tires back and forth.
Check toe, alignment, bearings, and the other general stuff that will cause it to tug.

Now that the easy junk is out of the way reconnect your ram linkage and turn the ram lock to lock very slowly. Do this a few times. What you are looking for is any point where the orbital has a looser or harder feel that would give the impression of a point within the system that has a internal leak.
If you have this you get to start off by getting some type of inline pressure gauge. Most tractor stores have them if you ask. Having two of these will make checking the system a lot easier.

This method does take forever. But it works great compared to simply tearing things apart and rebuilding them. It requires you to remove part of the system install gauges then bleed the system then check the reading at the gauge.

Start off checking the ram for the seal leaking by simply installing the gauges at both ports and then turning the wheel to the left then to the right.
The pressure should be the same. If not you most likely have some fluid leaking at the seals within the cylinder.

Pressure equal? Remove the inline gauges and reinstall the lines. Now you get to check your lines. This is more of a thing where part of the orbital/ram/seal has busted sending part inside of the line. Remove them and check for anything inside. Check the lines going from the pump to the orbital at the same time to avoid bleeding your system a second time later. Nothing? Reinstall them and move on.

Now for the frigging orbital. Grab the gauges that you used earlier and check for pressure differences between the pressure side and the output side of the orbital for internal seal leaks once again. There will be a difference of course. What you need to compare is the difference between the port going to the "left" side of the ram and the right. Now that you know that the ram is good any difference here will suggest you have an internal leak at the orbital. If all good then move on.

Now your left with the pump. This one is simple. Drop the truck back to the ground. Remove the pressure line(s) at the orbital or through firewall port and pull them over the grill so they hang over the ground. Grab a empty gallon of milk, Drill two holes so your lines will just pass through. Clean it out then cram it into the top of the pump. Use duct tape at the neck to avoid fluid coming out at the neck and tie the jug to engine so it does not move.

Now, remove the pressure line(s) and install the gauge(s) between the pump and line(s) then shove the lines into the milk jug. Fill the pump with fluid. Turn the engine over 20 or so times with the coil wire removed topping the pump off as needed then reconnect it the coil. Fire up the engine and then watch the gauge as you or someone holds the engine at a constant rpm. Is the pump pressure fluctuating?

If all your pressures are good you can begin looking at any type of regulator/centering valve and if it or the entire system is designed properly. Basically did it work great before or is it bran new? If bran new this stinking step applies.

Best of luck to you.
 
#14 ·
I have a single ended ram, not sure on the orbital. I replaced the lowers and it drove like total ass. Turned out my caster was way off. Adjusted it to -5 and it is back to good road manners. Worth putting an angle finder on it. That being said, feva is probably correct, buy an orbital.

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