3cx steering problem (there's none)

[paulmmc]

Hi guys.
I was happily using my Black cab 3cx (2wd non turbo) yesterday when suddenly the steering went. As it is purely hydraulic this obviously means I have no manual steering either so I have absolutely no steering, I managed to park it up by resting on the front loader and pushing myself sideways with the backhoe, slow but it worked. Forwards and backwards drive and all other hydraulics work perfectly, I have been through all movements through their full range of motion.
Anyway, I had a chance to look today and there was a hose peeing out fluid from where it joined the steering joint at the end of the steering column with the large bore hose running along the chassis rail. Where the hose burst it was well chafed so could have happened anytime.
Anyway, i replaced the hose and topped up the hydraulic fluid and still no steering. I emptied the hydraulic tank and removed and cleaned the pick up strainer to the power steering pump but it was pretty clean anyway and made no difference.
As the steering was fine until it stopped completely, I have to assume the pump and steering box is fine, my assumption is it is an airlock caused by the loss of fluid and the new hose, but I can not bleed it. Do I just keep loosening unions from the pump working towards the steering column and then to the ram? The steering failed at full lock so i opened the ram hoses slighlty to allow me to straighten the the wheels by pushing on them, which worked fine. I don't have a suitable pressure guage to check the flow from the pump but I find it hard to believe the pump failed at the same time as the hose burst just by coincidence.
Any advice greatly appreciated as I do not what else to do.
Thanks in advance,
Paul

[essexpete]

Most hydraulic steering can be bled by turning from lock to lock. Is the steering wheel just turning without moving anything?

[paulmmc]

Yes, the steering wheel will just spin indefinetly with no resistance, looking at the base of the steering column it is spinning above and below the rubber damper (donut thing). I have had the wheels up in the air and spun the wheel loads in either direction wth no improvement at all.

[paulmmc]

Just trying it again today, with the engine off turning the wheel feels a bot notchy, i assume because there is no oil being pumped to it, i cant feel any notchiness when the engine is on but I'm not sure if this is because the vibrations from the engine are hiding it or if oil being pumped to it is picking up the slack.

[diggerjones]

My digger has separate pump and resivoir. Not a jcb though. But has perkins in it

[paulmmc]

These do have separate pumps for power steering and all other hydrulics, but share a reservoir.

[harry]

Common problem with 3cx black cab is the steeringschaft into the steering unit ( orbitrol ) .
Dust and fine sand from the floor goes down the splined schaft and pushes the splined schaft up out of the steering unit after time !
Make sure the orbitrol itself is turning if you turn the steeringwheel .

Succes,
Harry

[paulmmc]

Harry, thanks for pointing me in the right direction, although the problem is not that it has been pushed out but that the steering column has somehow dropped to far into the Orbitrol. If i pull the whole column upwards then the shafts renegage, as a temporary fix i have loosened the fixing plate at the base of the steering column (below the rubber donut) and packed it with a couple of washers, but it still needs the odd yank to renegage the shaft.
Hopefully when i remove the whole column there will be some where i can adjust its position as a permanent fix. The problem looks to be caused by the base of the steering column wearing away where it touches the retainign plate, maybe the sudden loss of oil pressure due ot the burst pipe caused it to drop slightly?
Anyway, thanks for all the replies.
Regards,
Paul

[harry]

You're welcome. Hope you can fix it permanently .
Succes,
Harry

[paulmmc]

Just a final update, my bodge didnt last very long so i took out the steering colum yesterday and the splines at the bottom of the steering coupler (where it enters the Orbitrol) had worn completely away, thankfully the Orbitrol is undamaged. The reason it failed after the hose went is that the power assist obviously failed when the hose burst meaning extra stress was put on the remaining splines which sheared whatever was remaining. Pulling up the column worked for a while as the splines at the base of the column were less worn, but as these were only a couple of milimitres long it couldnt take the stress.
Anyway, while I wait on the new coupling (a bargain at £17.50 delivered from the UK!!!), i shortened the the base of the steering coupling so that the undamaged splines which could not previously go far enough into the orbitrol now go in which will keep me going for today, but it means I can not fit the retaining plate as it would stop the splines going deep enough so if i pull up on the steering wheel it will pop out, but its easy to put it back in, like I said, another bodge to keep me going for the day.
An interesting thing i learnt is that i do now have manual seering when the engine is off whereas I didnt previously, this shows how worn the splines were as they could only offer enough resistance to turn the wheels with hydraulic assist, as soon as oil pressure was gone the splines on the steering coupling just slipped over the orbitrol splines.
Hope this helps.