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Hydro Assist (Some explaining required please) ?


zim
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Hello,

I've spent hours searching through this forum and other sites for people who've done this, and think i know roughly what's needed.

This one in particular being a great help - http://forums.lr4x4.com/index.php?showtopi...hl=hydro+assist

But what i haven't read about is how it actually works.

Maybe because i don't know exactly how a power steering box works ? My little brain understands it as follows :

Your steering column is effectively connected to your drag link arm via a torsion bar.

As you turn your steering, the torque twists the torsion bar, and in doing so opens valves to allow fluid to pass / flow / push thus making your steering easier.

Now maybe i'm totally wrong with this explanation, so feel free to laugh at me :P:o

What i was wondering about was, how do you make sure on a hydro assist system the correct amount of fluid fills the ram to match the steering box. Say for instance you were turning right, if your steering box arm was all the way to the right how is it ensured that the ram has enough fluid in it to extend the correct distance.

i.e. too much extension, and something will break.

I hope the above makes sense ?

Gordon

this is the sort of application i'm referring to (pic from other thread)

post-9903-1216286952_thumb.jpg

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To begin, the steering box has a ram inside which adds power assistance to the steering in the same direction as the wheel is turned, this is controlled by the valve as discussed here.

The ram lives inside the body of the box at the bottom and pushes a rack on the pinion machined into the sector shaft.

6024d1211880041-four-bolt-steering-box-steeringbox2.jpg

6025d1211880041-four-bolt-steering-box-steeringbox3.jpg

Pictures borrowed from landyzone.

Adding hydraulic assist to your steering setup is, in effect, running the ram on the axle in parallel to the existing ram in the box, therefore the flow will fill both rams to the same pressure but the pressure will act on a greater surface area so giving more steering force.

I hope that makes sense.

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I have had fitted fitted hydro assist to my vehicle for the year or so and as such have put another onto Gwyn Lewis's truck and supplied another for Adrian to destroy / (constructively) complain about.

I have been working on my hydro assist with input from a good freind of mine Gwyn Lewis and pipework supplied by Dave Lama.

I have written a set of fitting instructions complete with pictures and wish I had the one above whilst I was doing it.

I have been tempted to post these fitting instructions allong with my reasons for why I have made up my kit in the way I have, but dont want to come across as doing blatant advertising.

I would though be interested in moderators opinions especially as some of them are making up kits for their own vehicles.

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I fear I could be opening a can of worms.

I have spent some time talking to the people at adwest at billing over the last 3 years who supply 275? power steering boxes per week to Landover.

It is their explanation of how the power steering box works plus googling a few American web sites that has enabled me to have a better understanding of how the Landover power steering works.

The representative I spoke to from adwest this time spoke to me about his conserves with increasing the pressure/flow of oil into the standard power steering box, he showed me how this could eventually lead to bearing failure in the upper chamber (item 8 in rogevouge'pic) which could then cause debris to fall and jam the gear and rack (item 15 and 1) with disastrous results.

At the same time as giving me this explanation he was also truing to sell me their higher strength version box £575 which was basically a heavy duty defender box with disco 2 internals.

The design of system I have at the moment is designed to be a straight forward no welding, drilling or machining required fit, as such I am aware of some slight drawbacks.

I can see how I can improve it using a discovery drop arm instead of defender and as such I intend on looking into the availability of parts and the lightly additional costs.

I shall upload my pics then cut and paste my word document accross.

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Installation instructions for damper replacement hydro assist.

Ensure that your comprehensive kit of parts supplied is complete.

Parts in the kit consist of:-

2 Hydraulic fittings for the top and bottom of the power steering box,

2 Copper washers for the above fittings,

1 Adapter fitting to go into the bleed nipple of the power steering box,

2 Hydraulic fittings to go into the assist a ram,

2 Dowty washers for the above fittings,

1 Tee piece fitting.

1 300mm braided hose pipe,

1 600mm braided hose pipe,

1 900mm braided hose pipe,

1 Rose joint complete with bushing,

1 Modified hydraulic ram,

2 Polypropylene bushes,

1 Modified domed washer,

1 Nylock nut.

Tools you will need:-

9/16” spanner,

22mm spanner,

17mm spanner x2,

19mm spanner,

Container for catching old power steering oil,

Replacement power steering oil,

Park your Landrover on firm level ground ensuring the hand brake is applied.

Carefully clean around the whole of your power steering box to ensure there is no risk of dirt entering the hydraulic system when pipes or fittings are removed.

Remove the original steering damper from chassis end (19mm spanner) and from steering rod (17mm spanner x 2)

Retain the m10 bolt and nut removed from the steering rod end of the old steering damper for use later.

Using a 9/16” spanner remove the link pipe that goes from the top of your power steering box to the bottom of your power steering box.

Image060Small.jpg

Power steering fluid will leak out of the 2 corresponding holes once this pipe is removed ensure you catch this waste oil with an appropriate container.

Fit the 2 hydraulic fittings for the top and bottom of the power steering box complete with their corresponding copper washers to ensure they do not leak.

Image061Small.jpg

Fit the supplied tee piece to the bottom fitting (leave slightly loose until pipe work is fitted).

Image062Small.jpg

Remove the bleed nipple from the top of your power steering box, replace the bleed nipple with the supplied adapter fitting. Retain the bleed nipple somewhere safe in your vehicle should you need to revert your steering back to normal in the future.

Assembly of the assister ram

Ensure the rose joint is securely attached to the end of the ram piston and slide one polypropylene bush onto the pin on the other end.

Push the bush end of the ram through the fixing position hole at the chassis end.

Slide on the second polypropylene bush followed by the modified washer.

Wind on the nylock nut and tighten with a 22mm spanner.

Remove the 2 protective dust caps from the ports of the assist a ram.

Pull the piston out of the ram until the rose joint lines up with the fixing position on the steering rod.

Fit the m10 bolt that had been saved when removing the steering damper earlier.

Attach the 2 hydraulic fittings to the assist a ram complete with the supplied dowty washers.

Image065Small.jpg

Assembly of braided hydraulic pipe work

Leave all pipe fittings loose until you are happy with their position and routing, the JIC fittings on the pipe work provided requires tightening down finger tight then turning one more flat with a spanner .

Run the shortest of the 3 pipes from the top rear of the power steering box down to the tee piece.

(this pipe is long enough to route along the same position as the original link pipe or along the top and then drop down as I have done)

Run the middle length pipe from the tee piece to the assist a ram fitting closest to the piston rod.

Image066Small.jpg

Run the longest length pipe from the bleed nipple position down to assist a ram fitting closest to the chassis.

With all three pipes loosely fitted it should be possible to adjust their position such that there are no sharp kinks in the hoses or any chance of the pipes either rubbing on any engine or body components.

Once happy tighten up all fittings.

Power steering oil re fill

Fill up the reservoir of the power steering system with the appropriate power steering oil.

Start up the engine and top up the fluid reservoir.

With the engine still running slowly turn the steering from lock to lock.

With the wheels pointing forward check the reservoir and top up as necessary.

Finally check all fittings for leaks.

Steering system restore

Should you need to temporarily restore the power steering system back to original simply slacken the hose that fits to the original bleed nipple position, undo the adapter fitting and re fit your original bleed screw, remove the short pipe from the tee piece, remove the tee piece and fit the short pipe into the hydraulic fitting.

Enjoy!

Disclaimer

This assist a ram kit is intended for the assistance of the steering when coupled with larger than normal sized off road tyres.

As such it has not been homologated for use on the road.

It is your responsibility to familiarize yourself with the changed behaviour of your steering system.

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Rob - do you have a price for your kit?

If you can't give prices out on the forum, then a PM would be good.

We need to come over to Gwyn's soon to pick some more bits up before Kirton, so it would be good to be able to get a kit installed ready........

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I have run this kit on my vehicle for the past year or so but was hoping to get feedback from the few I have supplied before releasing for general sale.

As such I currently only have one kit in stock and replace it as it is sold.

I'll send you a pm with my price and phone number.

I highly advice you have a chat with me regarding the issues I can explain to you about this before you purchase.

I hope to discuss these issues I have on line over the next few days.

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I have run this kit on my vehicle for the past year or so but was hoping to get feedback from the few I have supplied before releasing for general sale.

As such I currently only have one kit in stock and replace it as it is sold.

I'll send you a pm with my price and phone number.

I highly advice you have a chat with me regarding the issues I can explain to you about this before you purchase.

I hope to discuss these issues I have on line over the next few days.

Hi Rob,

Looking forward to seeing this as I would also be interested. I do not seem to be able to PM you.

Mark

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Some more pics of the ram mounting please

and do you use the original swan neck to mount the ram to?

as I was warned off of using it.

Does the pump you use offer enough flow?

does the ram keep up with the steering box

what is it like on the road

and the price please

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I fear I could be opening a can of worms.

The representative I spoke to from adwest this time spoke to me about his conserves with increasing the pressure/flow of oil into the standard power steering box, he showed me how this could eventually lead to bearing failure in the upper chamber (item 8 in rogevouge'pic) which could then cause debris to fall and jam the gear and rack (item 15 and 1) with disastrous results.

A valid point in theory but in practice they seem to be fine. I have been running high output pumps for a long while as have many others without any problem. And lets face it, What parts on our landrovers arn't being used above and beyond what they were designed for?

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And lets face it, What parts on our landrovers arn't being used above and beyond what they were designed for?

Interior mirror :unsure: ?

:lol:

Rob, i had a real good look at Billing and i think it is a cracking little kit, Big thumbs up from me.

Jim

Ps: when could you deliver a set?

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Some more pics of the ram mounting please

The ram is mounted exactly as per standard steering damper.

and do you use the original swan neck to mount the ram to?

I do use the original swan neck ( on my own vehicle I am using a discovery drop arm and have then welded tabs to my hd steering rod to emulate the swan neck damper mounting)

as I was warned off of using it.

There is debate as to the strength of the swan neck but that is not the reason I don't use it, a disco track rod end is quicker and easyer to replace than the ball joint in the defender drop arm.

Does the pump you use offer enough flow?

This is one of the reasons that my assist a ram is only 25mm bore, having experemented with 40 mm bore the steering was super strong and feather light ( I could turn the wheels when they were buried in mud and I was nose down in a hole and the rear of the vehicle would move accross) but I couldn't turn the wheeel acceptably fast.

I have developed this Hydro Assist to be a straight forward easy fitt, the kit can be improved but where do you draw the line on how much money you spend.

does the ram keep up with the steering box

The purist will notice a difference and as such I would never recomend it for a comp safari vehicle, for challenge use I am more than hapy with it, I would like people to have tried it out for themselves before comiting to purchase.

what is it like on the road.

I am happy with it but to give a definative opinion here is something I would be causious about.

and the price please

I have a rough gude price in mind.

Give Gwyn Lewis a ring as I intend on selling through him initially(ability to take card payments, mail order ability,Vat issues)

Dave Lama and Jim Gigglepin have expressed an interest in selling this kit.

Hold on a little as I havent the finances to hold large stocks and need to evaluate liability issues before producing loads of these kits.

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I should have 5 kits complete by Friday afternoon 1/8/08 I have got all the components together I just need to do a bit of fabrication and painting.

I had a report back from Red 90 driver (Nick) today his coments have pointed out a flaw in my fitting instructions but were otherwise very satisfactory.

During fitting there is no clearindication as to how the pipes are routed.

This was deliberate by me as different engine/radiator examples could possibly mean that the pipes end up being routed differently.

Iintend on taking some more better quality photos over the week end.

I appear to have lost steering lock in one direction.

The travel/stroke of the assist a ram is very close to the travel of the steering rod.

I have fabricated the Assist a ram to fitt in place of the steering damper with the front steering rod in its factory position.

If you have fitted longer or shorter after marked front steering rods you will need to adjust the length of the front rod.

On full left hand lock(steering held tight left hand down the rod of the Assist A Ram is both fully into its cylinder and not obstructing steering travel.

The travel can be checked by removing the m10 bolt from the drop arm end of the steering rodand ensuring the steering wont move any further or the rod go in any more than 5mm.

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Good reply there :)

Is the above method better than drilling & tapping either side of your steering box (i'm asuming if you do this, you can possibly use bigger fittings) ?

What ends are on the ram ? swivels or just a bush ??

How long is the ram, and what length of stroke ?

thanks

Gordon

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Rob - that loos good!

I had a chat with a chap from Adwest at Billing about supplying boxes adapted to run power-assist. He went off the deep end at me suggesting I was criminally negligent even suggesting it! I then introduced myself properly and his tone changed completely! I guess he was just trying to stop the hard-of-thinking playing with things which could be catastrophic on the road if they go wrong!

He mentioned the chap who's Land Rover went off the motorway and caused a train crash. He apparently had an Adwest steering box and his defense in court was that the box had failed causing the crash. They had to go to some extreme lengths to prove the box had not failed - otherwise, I dare say they would have been in the dock. I found that a bit sobering.

He said they were working on a higher flow/pressure rotary valve (similar to those fitted to some cars with power steering) which is fitted in line with the input to the box. This struck me as an excellent idea. At least, if it fails, you still have the steering box intact and from their point of view, the potential liability is much reduced. No idea about timescales though.

Si

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Si, a very valid point that anyone making kits for anyone else should think about. Rob, you want to make sure anything you sell is sold as a collection of parts that could be made into a hydro assist kit if you so wish and that the instructions are simply how you did it. Its not so much a problem of people you sell it to claiming but what about their families if they were injured/killed or the other party in an RTA. Very sobering.....

I'm not surprised at Adwest's response - you know what they say about a little knowledge being a dangerous thing.

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