That's a great explenation of the Hicas system Eric! :zlove: ...but on top of what you explained, would you say it's fair that if one of the side seals of the Hicas unit did in fact blow, that it would leak Power Steering fluid from that point? and to the point that there would no doubt be stacks of fluid dumped from that point - also clearly showing a lowered resovoir level? ...Enigma, can you also confirm these visuals?
To my knowledge, there has never been one solitary documented scrap of evidence to support all the hysteria directed at the HICAS fitted to NISSAN models. If there was, it is inconceivable that this system would still be legal for a road going vehicle. This is not, nor should it ever be considered as, an attempt to ridicule Enigma. Clearly something happened to cause his accident. From the pictures seen so far(and from the sketchy description of occurrences during the event)it appears to me that the left rear wheel may have come into violent contact with the left-hand kerb at the precise moment Enigma was entering the round-a-bout(this is very easy to do at speed)and the subsequent unsettling of the car has brought about the reported result. Main thing is, neither passenger was injured and this is something to be very thankful for. Cars can be repaired or replaced, people can't! Hope it all works out for you guys. Lloyd:zlove::zlove:
Benny, if it was a gland seal(side seal) that failed, fluid would have leaked externally. I would say a piston seal failed. Look at this picture, The 3 grey stripes in the centre are the piston seals, if one of the outer piston seals leaks, it will flow oil directly to the other side. This is not a hicas link, but all cylinders of this type are very similar. Chili, while I agree that the hicas is a very reliable system being hydraulic it is still not uncommon for it to fail or behave unpreditably. The maintenance manual states steering fliud should be check for condition or replaced every 20000km, it only takes a small ammount of contamination to upset the system. A slither of metal off a piston or bore can easliy find it's way into the seals. This does not happen very often in the hicas but is a frequent occurance in hydraulics used in most other machinery. Nissan did a very good job on our cars but it can fail unexpectedly. edit, Chris,if you are the one doing the repair, can you rip the hicas apart and see what happened?
On top of all that which I have just written. A similar thing can occur if the hicas solenoid spool were to stickat one point, although this should not give excees rear steer travel over the standard ammount due to the flow control valve over-riding the solenoid spool. This is a spool valve, those that have pulled apart an automatic trans valve body will have seen a few of these. They are what is called a class fit, meaning machined to very fine tolerances to the bore they mate with. There a no seals on these, relying only on the fit to seal the spool in the bore giving close to zero leakage between sections. Obviously with such tight clearance it takes very little debris to score the valve and housing, this leads to galling and soon enough the spool will stick or even sieze. Spool valves usually have quite heavy springs in them to regulate thier movement, these also return them to position so it usually works pretty well. Like I said earlier, hydraulics are very reliable, but they fail like everything else. Most heavy machines use rotary spool valves or orbitals as they are commonly known, connected directly to the steering shaft, meaning no mechanical contact at all with the wheels. These usually need work every 5000 hours or so, and steer rams usually every 3000 hours or less due to the operating enviroment. Very robust, but not perfect.
You make some very compelling points(and I am not about to contradict your logic). I have never had one single incident in 10 years of ownership of my TT which could be seen as HICAS related. That said, I have NEVER been aware of any lack of predictability during many very quick klm's of driving, on some very twisting roads. However, I have just removed my HICAS in the past week(replacing it with new steering arms/ball joints and Lockout Bar). This was done in conjunction with fitting new Racing Gear shocks and springs and a new set of N6000 tyres. I am anxious to see if I can "feel" any difference in the predictability of "CHILI"(so far none to report)but the changes all occurring simultaneously will no doubt disguise which item has brought about any noticeable difference, if such exists.
I have repaired a few hicas systems with strange issues, most of which feel like a loose rear cradle, gerenally lapping the spool in the solenoid fixes this. I do like a working hicas however non hicas cars feel a little more predictable to me. That could be because I rarely drive our own car and am always driving many different 300zx's with varying mods and in varying states of repair/neglect.
I should note that just because your car doesn't have this fault it doesn't mean other cars don't. It may be down to maintenance, and I presume yours has 10 years of reputable history in comparison to the unknown history of Adam's car. I think the debate on whether or not HICAS is the problem is a bit lacking in evidence on all sides... It seems we will have to wait until someone can fully inspect the rear cradle and the HICAS system to see what actually went wrong. As for cursed cars Adam, have you seen Wangan Midnight? Basic Wangan Midnight plot outline: If the previous owner shares your name, I'd watch out! :O
I understand what you are saying but if you look at the photo's you wll see that it is a two lane road and roundabout. As I stated before, the road is new, smooth, clean and wide. My point being - I was well away from the left and right hand curbs upon entering and travelling through the roundabout. If my only problem was bad driving, believe me I'd be much better off LMAO. I would love to show you guys the actual place this happened and you too would be convinced that this was not an environmental cause, this was the vehicle. Anyway we will all find out soon.
As I stated previously, this was not intended as a slur on your driving ability. I am as guilty as the next guy, in having endeavored to use "every last mm of available roadway" in the heat of the moment(only to misjudge the limit to what is actually "available").
i agree ,not saying anything bad against anyone but i drove tow trucks for many years ,it looks like you lost traction and yeah she turned you guys around, glad no one was hurt ,shame your zed got hurt ,
