Front suspension stuck

[davidwheeler]

Boot's front suspension is stuck at the top of its travel.   It is well lubricated and steers albeit a bit stiffly.  This used to happen with Sheila before I rebuilt the suspension and would return if I jacked it up and turned from lock to lock as few times or occasionally spontaneously.  No such luck here.  The suspension was rebuilt a few years ago after the crash with new pillars etc.  Questions are;
Why?
How do I get it back to normal again?
How do I prevent it happening again?

[Dilambdaman]

Hello David,

Could it be that one of the valves which allow the oil to travel between  the top and bottom chambers has either failed or become blocked? Could a broken spring jam the piston? I fear that dismantling the sliding pillar may be the only solution. 

Robin.

[davidwheeler]

Actually it popped back down while I was gently tapping the upper (locking) ring retaining the lower suspension cup/sleeve (11108).  I was going to remove the cup in order to release the pillar but now not necessary so have done it up again.  Cup itself was not loosened as I did not get as far as the lower ring.  I'm sure it is not the valve, it is too on/off.  The springs are new ones so unlikely to have broken and now the suspension rests equally both sides.  I suspect that the bottom end of the pillar is getting jammed in the top of the cup because of coming just a little too far out but I cannot see why that should be so.  Sheila had actually broken the ring on the stub axle that fits round the pillar but that does not seem to have happened here.
Incidentally, if the Aprilia hits a really big pothole the same thing happens despite all new bearing surfaces.

[the.cern]

I am pleased to find that you have sorted the problem.

You now know that the judicious use of a hammer will solve the problem. Jim recommends the use of a hammer when something is reluctant to shift. This is not ignorance or frustration, it is, and I quote, "just getting its attention".

It usually works!!!

                             Andy

[davidwheeler]

The late great Wing Commander Neville Buckle, who only ever drove a Lambda, used to say he could fix everything with "an ajustable spanner and a copper hammer" which latter item has ever since been known in our family as a "Buckle".  I used a much more delicate tool and I think it was really a matter of leaving it jacked up for a few hours!    Still does not answer questions 1 and 3 though.