Home Brew Steering
 

Read first.....

http://www.pirate4x4.com/tech/billav...ng/index2.html

Have Orbital Valve and Ram..........have 351 Cleveland to drive the Pump, so thinking power steering pump.............and then..........

Mate - I hope that ram is going to work out for you.
Where did you get the orbital valve?

Quote - "Enterprising 'wheelers initially began by adapting agricultural and industrial hydrostatic steering systems to recreational 4x4s. However, due to the nature of hydrostatic steering, this approach can have wildly varying results, depending on the match between the steering system being cannibalized or emulated, and the desired performance of the 4x4 in question."

Drop Shane a line if you want to chat about his setup.
He might run into some similar issues or have some good tips.

cheers

z

The differance with Shanes is that it was an imported kit, this thing I am trying to understand and build is a budget system to try and get to work. Have spoken to lots of people, and yeah can get off the shelf kits from min of $2500 (which I dont have spare) but wheres the fun in that, wanna try and learn and develop. Not everyone has mega bucks, and getting back to my inital plans of this rig, its a budget build.

ps. no disrespect intended towards shane on the cash expenses.

I fully understand what you are trying to accomplish and think it is cool that you are building to a budget.

The reason I told you to drop Shane a line is so that he can share the knowledge has has gained through installing the full hydro on his jeep.
Even though he bought a "kit" from ABT/USA there was still a lot of custom stuff to to get it working, and even now he is redoing some of it to incorporate a big fluid cooler and shorten up the lines.
It has not been a simple bolt in job at all.

Just thought he would have some valuable info thats all.

cheers

z

i have built a couple of systems using the forklift/ag gear, it is pretty easy, but there is a couple of things to watch out for. first thing is to make sure your orbital is open centre. easiest way to do this is hook all your lines up, leave the low pressure return line sitting in the top of the resivoir, fire the motor up with the steering sitting idle, and make sure there is fluid running back out the return line. a closed centre valve won't do this, and will destroy your pump straight away. the next thing is to make sure the valve is not load reactive. load reactive valving works very well with a double ended, balanced ram, but it will not work with your single ended ram, and will eventually destroy the valve.
you also want to make your low pressure return line as big as possible. i think my last setup was 9/16" pressure lines and 3/4" return line.
if your motor has the big ford teardrop style pump with the built in resivoir you are laughing, you get a big res (you need this with a single ended ram as the fluid level needs to rise and fall with the ram action) and the res is built onto the pump, so you don't need another short line between res and pump. they also have a vented cap, so you can get rid of the relief valve in your drawing, but you really should look at sealing the cap and running a vent hose off it. that shit gets messy when you are upside-down.

Hey Jimmy,

I can't say that I have a huge amount of experience with setting up hydro systems, but I did do my research and chose the kit that would give me the most complete system, at a good price, and with proven performance. I also had a hydro assist system to sell to offset the cost, and the POS kit comes with heim joints and clevis ends so it is very complete. With the double ended cylinder you don't need a tie rod, so that saved some $$ as well.

When I did the math, I found that for me it was cheaper to go full hydro through POS and Sean at ABT rather than re-working my hydro assist system...

That's why I went with the double ended cylinder POS setup through Sean at ABT... this is the same system as Bill is talking about in the link that you have above.

Here's a few things I have picked up - and take note of Wendle's too. The vacuum line from the reservoir to the pump should be as short as possible, and at least -10 rated. In general I have seen recomendations of no longer than 16" in places, and no longer than a couple of feet in places, and no longer than a foot in places... basically as short as possible, and keep the vented reservoir as high as possible.

Mounting the control valve with the ports facing up is also important.

And make sure you factor hydro lines into your build up budget, because they aint cheap and you need to go for quality crimped fittings on quality lines if you want reliability.

I am also adding a cooler to my system - recommended by POS, but haven't got it in yet. Cummins were kind enough to donate me a brand spankin oil cooler (heat exchanger) with 1/2" lines (tube and fin style) and 1/2" fittings... the fittings should be 1/2" or -8 otherwise the pressure drop across the cooler will be too large, and you can actually heat the fluid rather than cool it. If the line between the reservoir and the pump is too long the back pressure can cause cavitation in the pump and aerate the fluid (trust me on this one). Running without a cooler can cause the same thing as the vapour pressure of the hot fluid rises.

And finally, the pump, control valve, and cylinder are matched to give you your desired performance. This depends on the type of cylinder, flow of the pump, and the control valve. I asked for about 3 turns lock to lock, and that's what I got.

I'm sure there's more, but that's what I can think of off the top of my head.

Good luck with whatever you decide to go with.

S.

Thanks guys, some good feedback there. I guess my other motivation behind building the system up is to learn more and understand what does what a bit better. Its funny how a off the shelf kits seems to leave a bit to be desired in terms of coolers etc. Seems it is more a starter kit in some respects? Will be getting Enzed to cruise up and plumb it all in for me when the time comes.

Have the tie rod section sussed, and think we have worked out how the spear will be mounted, the tie rod will be going up, ie doing a high steer conversion on the existing setup but will use joints at the end.

Will be rewarding once its all working, but I can only see from what I am reading that getting it all working is part a, part b is getting it to run right :)