fittered a SAS to the road sweeper i have both mannel switch and remote switch and they work fine i would be looking at the way its wired up

From the website picture page of the unit it looks like you could do the following:

If you have the gauge installed you could loosen one of the fittings CAREFULLY and bleed it slowly from there. I suggest you loosen the fitting at the back of the gauge; or

if the gauge is not installed you could loosen the gauge port plug CAREFULLY (located on the right hand side centre of the right ram cylinder) just enough to bleed air slowly.

If the unit is pumped to full pressure you could be dealing with up to 100psi captured in the system so caution advised when bleeding anything from fittings or ports.

Just my 2 cents....