[Richard]

Yeah, I have had to replacemthat regulator due to leaking.

There are a few lines leaving that area to feed the doors and potties. You could disconnect and cap the feed one at a time. Or do it the redneck richard way and pinch the line with the smooth jaws of visegrips. Or do it the Steve Bare way and install the isolator on the airlines one at a time to narrow it down. There is simple work to be done right around the pump that can save hours removing interior panels