stuck Posted August 11, 2009 Share Posted August 11, 2009 Hi all, I'm looking for information regarding how to go for true hydraulic steering rather than PAS, I've searched the forum but haven't found anything so far. Would greatly appreciate any information on: a) how to do it. b) if such a system would be road legal. Many thanks, Mick. Quote Link to comment Share on other sites More sharing options...
carl hurst Posted August 11, 2009 Share Posted August 11, 2009 b) if such a system would be road legal. To be fully road legal as i understand it has to have a mechanical link so as full hydro has no link then no road legal, some people including myself are looking at ways to have a mechanical link on full hydro but its early days and not sorted anything yet but it is posable, i hope anyway, Carl. Quote Link to comment Share on other sites More sharing options...
landmannnn Posted August 11, 2009 Share Posted August 11, 2009 Do a google search for Full hydro steering, plenty of write ups. It is only legal if you register your motor as agricultural. Quote Link to comment Share on other sites More sharing options...
carl hurst Posted August 11, 2009 Share Posted August 11, 2009 I you register as agricultural are you not on limited use, so cant go very far, Carl. Quote Link to comment Share on other sites More sharing options...
alan kemp Posted August 12, 2009 Share Posted August 12, 2009 I spoke to sva man and took mine to show him. It would never pass an sva without "a backup to steer the vehicle if the hydraulics fail". I think we have the problem cracked to be road legal and sva'd but I wont know until it is all built. Interestingly, I asked what would happen if they pulled my existing truck up with full hydro at a VOSA inspection point, he said as long as it has an MOT it will be fine!! (That is only his opinion though and I would like to be assured that that is the case before I use mine regularly on the road). They are fully aware that a miriad of mods go on with vehicles, not just off roaders, after they have been sva'd. Quote Link to comment Share on other sites More sharing options...
FLR100 Posted August 13, 2009 Share Posted August 13, 2009 when i fitted full hydro to my truck i asked my regular mot guy if he was legitamtley allowed to pass it and he basically said so long as everything was attached securely and no excesive play in joints ect like he would test a conventional system then he would have no problem putting his name on an mot certificate, i never botherd presenting it for a mot in the end as i really could not be botherd to sort lights out ect on another thought the steering must be pretty scary on the road as when i have got upto any speed on a good flat surface the steering does not self centre meaning you are constantly correcting it, or is it just my truck? Quote Link to comment Share on other sites More sharing options...
zim Posted August 14, 2009 Share Posted August 14, 2009 There is a very good write up i found on www.Pirate4x4.com . Sorry, but this internet connection is too slow to give you a link, but well worth looking on there (in the technical section i think it was). G Quote Link to comment Share on other sites More sharing options...
p38rr Posted August 14, 2009 Share Posted August 14, 2009 Steering for a class 4 vehicle MOT has to be mechanical but can have hydraulic assistance (pas). Any vehicle with fully hydraulic steering should NOT pass a class 4 test. Agricultural vehicles do not need an MOT. If anybody has a class 4 vehicle with an MOT with fully hydraulic steering basically shouldn`t have!!!, unless of course you have fitted it after it was MOT`d. Quote Link to comment Share on other sites More sharing options...
alan kemp Posted August 15, 2009 Share Posted August 15, 2009 Steering for a class 4 vehicle MOT has to be mechanical but can have hydraulic assistance (pas). Any vehicle with fully hydraulic steering should NOT pass a class 4 test. Agricultural vehicles do not need an MOT. If anybody has a class 4 vehicle with an MOT with fully hydraulic steering basically shouldn`t have!!!, unless of course you have fitted it after it was MOT`d. Mine has passed 3 MOT's with full hydro. There is no mention oa a "mechanical" link in the MOT or SVA/IVA. There is a mention in SVA/IVA about a back up or fail safe to be incorporated. Quote Link to comment Share on other sites More sharing options...
Orgasmic Farmer Posted August 15, 2009 Share Posted August 15, 2009 Interestingly I was havinbg a look at the steering on a JCB Fastrac the other day and because this is capable of speeds in excess of 20 mph it seems it too has to have a mechanical link. Whereas all normal tractors have a full hydraulic setup the fastrac has a steering column to a proper steering box and PAS steering. How effective this would be in the event of PAS failure I have no idea as the steering wheel is tiny and the road wheels are huge and about 2 foot wide! But it seems that Full Hydro steer cannot be legal for road use at speeds of more than 20 MPH. Quote Link to comment Share on other sites More sharing options...
Taff Posted August 15, 2009 Share Posted August 15, 2009 My understanding is that a construction/agricultural machine can travel upto 40 kph or 25ish mph on full hydraulic steering. Anything over this speed must have a mechanical link to be legal. This is why there is a dispute within the tractor industry between JCB and the likes of Fendt as JCB quote that they are the only legal tractor on the road that will travel above 40kph. Plus within the hydraulic steering regulations for the machineries, if the machine travels between the speeds of 20 and 40 kph they do have to pass a number of steering tests. These consist of a straight line test to see if they wander out of the designated width, plus there is a slalom test that has to be conducted. All of these tests are conducted with and without hydraulic power being applied, at different speeds and with or without a load if the machine is for example a dumper. Due to these tests some machine (such as a wheel loader)run a back up hydraulic pump. These pumps vary from gearbox/axle driven to electrically power which cut in when the machine sensors a problem with the hydraulic circuit and a drop in the hydraulic pressure is sensered. But if a hose goes between the orbital and the steer cylinder this will not help you one bit, if this happens you have a steering wheel connected to the orbital, but you are not connected to the cylinder. I think that’s enough from me for now. I will get back in my box. Taff. Quote Link to comment Share on other sites More sharing options...
p38rr Posted August 15, 2009 Share Posted August 15, 2009 All class 4 vehicles MUST have a mechanical steering linkage and can not be fully hydraulic FACT. I have no intention of getting into a petty argument about this but I am right even if others don`t want it believe it. If you have passed an MOT with full hydraulic steering then good luck to you. You certainly would not have passed a SVA with it. Quote Link to comment Share on other sites More sharing options...
alan kemp Posted August 17, 2009 Share Posted August 17, 2009 All class 4 vehicles MUST have a mechanical steering linkage and can not be fully hydraulic FACT. I have no intention of getting into a petty argument about this but I am right even if others don`t want it believe it. If you have passed an MOT with full hydraulic steering then good luck to you. You certainly would not have passed a SVA with it. Hydraulic steering would not pass an SVA/IVA without a backup system. To pass the SVA/IVA, I am building the car with hydraulic steering and a mechanical link as that is the easiest way of getting the backup system. There is no mention (according to the SVA man at Bredbury VOSA station) of a mechanical link. Your steering must still operate in the event of a hose failure. I know from experience that you can still steer for approx 100 meters when a hose fails, (or a connector gets hit by something and breaks the seal) but this is not acceptable. For anyone who is interested, one of the tests they do is to park the front wheels on the turntables for the wheels and you have to be able to turn the steering from lock to lock without the hydraulics system working. Quote Link to comment Share on other sites More sharing options...
carl hurst Posted August 21, 2009 Share Posted August 21, 2009 All class 4 vehicles MUST have a mechanical steering linkage and can not be fully hydraulic FACT. I have no intention of getting into a petty argument about this but I am right even if others don`t want it believe it. If you have passed an MOT with full hydraulic steering then good luck to you. You certainly would not have passed a SVA with it. Out of pure interest i wounder what sva man would say about rear steer? After he stoped laughing of course, Carl. Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted August 21, 2009 Share Posted August 21, 2009 ^^^^^^^^^^^^^ :rofl: Nige Quote Link to comment Share on other sites More sharing options...
jimyd Posted August 22, 2009 Share Posted August 22, 2009 Hi all. I have been reading through the posts on hydro steer and has anybody come across the hydraulic steering on a Zetor tractor? This has its own belt driven hyd pump, res, ram, etc, but there is no orbital unit on the steering wheel, it uses a conventional steering type arm and some how assists the steering in the dirction required!(dont ask me how it works) As i understand it this would sort out the legal issue of the mechanical link,but dont know how it would perform on the road? I have driven one of these tractors and it did seem a little notchy on the steering, but it was an old tractor! However my thoughts were that if you fitted this system using an airconditioning pump clutch on the hyd pump, and had the ram on quick release couplings, the unit could be simply switched off and removed for road use. I found this quick link of a system http://www.powersteeringkit.com/zetor.html Quote Link to comment Share on other sites More sharing options...
stuck Posted August 22, 2009 Author Share Posted August 22, 2009 "My other Car is a Diesel" Shame on you Sir! Quote Link to comment Share on other sites More sharing options...
discomark10 Posted May 24, 2013 Share Posted May 24, 2013 Hi all. I have been reading through the posts on hydro steer and has anybody come across the hydraulic steering on a Zetor tractor? This has its own belt driven hyd pump, res, ram, etc, but there is no orbital unit on the steering wheel, it uses a conventional steering type arm and some how assists the steering in the dirction required!(dont ask me how it works) As i understand it this would sort out the legal issue of the mechanical link,but dont know how it would perform on the road? I have driven one of these tractors and it did seem a little notchy on the steering, but it was an old tractor! However my thoughts were that if you fitted this system using an airconditioning pump clutch on the hyd pump, and had the ram on quick release couplings, the unit could be simply switched off and removed for road use.I found this quick link of a system http://www.powersteeringkit.com/zetor.html I would guess its a bit like the hydro assist bolt kit. http://www.llama4x4.com/page3.htm Anybody use one of these? Are they any good? Quote Link to comment Share on other sites More sharing options...
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