Help Urgent my vans tried to kill me

[Gromett]

Just to clarify what I think has happened.


Imagine this rotated 90° anti clockwise.

To retract the leg oil is pushed under pressure into the retraction flow port. The valve closes and the pump switches off. The pressure is maintained in the leg purely by the valve and the piston seal.

My suspicion is that the piston seal is leaking allowing the hydraulic oil to leak around the piston and the pressure in both sides equalise. The weight of the piston and legs will pull this towards the ground. This will happen slowly depending on how big the leak around the piston seal is.

I suppose thinking about it, the leak could also be in the valve as well that controls the flow.

I think that the act of extending the leg all the way and then retracting it may have reseated the seal or cleared any contamination (rust, dirt etc) from the seal.

As I have said multiple times. Really is a guess and I have no experience to base this on.

 

[cornish boy]

You may well be right, but in post #1 the OP suggested that the jack was coming down under pressure as cable ties wouldn't hold it in position.

It would be extremely good luck for a seal set in a double acting cylinder to 'reseat or reseal'. In my early career, hydraulics formed 90% of my workload and while I would never admit to knowing everything, from the comfort of my armchair I favour this may yet be diagnosed as a result of a low voltage battery issue.