ksanturion10 wrote: 20 Dec 2020, 16:24
It seems you will have to invent new way for unstucking it. But, that you put the corrector back, doesn't mean you are on the money. You probably have already disturbed the fine tuning and...
Good point Martin

Adjustment is critical as small movements of the linkage to the ARB translate to large movements of the suspension.
The easiest way to prove that is to disconnect the 'dogbone' link and use the manual height control lever only and see if that allows the rear to fall..
If that fails, then disconnect both 'dogbone' and manual height linkages and the car should then sink. With no linkages attached the height corrector will assume a natural position that will correspond to the lowest height setting.
One trusts the rear arm bearings are not totally seized... Was the car ever at normal height or fully low? It's very unlikely for them to be so seized that no suspension movement at all is possible but...
Also, there has to be enough main-line hydraulic pressure available to overcome the pressure in the rear suspension cylinders and allow the anti-sink valves to switch.
Does the front rise and fall normally?
Due to how the weight in the back of the car regulates the rear brake force and by extension, the pressure in the rear hydraulic feed, often a big weight in the back can be required to get enough pressure...
Hence why I suggested a group of big mates bouncing in unison on the tailgate sill!