Will be interesting to hear what it does, couldnt seem to get much detail from the website.
Probably, soapy water time me thinks

. Although if you can hear it you may beable to feel/see it.
As the backs came up slowly, the tank could have been empty just raising on the compressor will be slow.
But that doesnt mean the compressor is not worn, as it must have been working overtime for the front leaks.
Try running it with the doors open so the compressor just fills the tank first, Then shut the door see if it rasies quicker.
Its not really a complicated system once you get your head around it good luck.
J