There was a bulletin on this years and years ago and as I recall it called for you to drop the differential down so you could get up there. You may be able to drop the gas tank to gain access to it but it can be done without it. The vapor recovery system on that tank is not sealed really, not like it is on a '96 and later OBDII car is. The short answer is no, it will not make your main pump whine, hiss, or whir. If it is doing that you probably have a problem with the pre-pump cavitating. The pre-pump hose may be ripped or knocked loose or the pre-pump could just be bad. Does it have a tendency to do it worse when you are below 1/2 a tank of gas? With the car running grab ahold of the inlet line to the main pump and squeeze it a little, can you feel the air bubbles going through it and are they in cadence with the noises that your main pump makes? If not then you could simply have a noisey main pump, but if so then you are pumping air as well as fuel into the main pump and everytime it hits an air pocket it whines.

Like I said in my previous post, I have always managed to get the clamp loose and the hose changed out without dropping fuel tanks or rear ends to accomplish it. But this is up to your technician and his tools and abilities. Is he a Volvo tech, has he done one of these before? I know I do not like having people tell me what to do but if he has no experience with this hose you might want to tell him that you can do it without dropping the tank. I access the clamp through the access panel in the trunk with a small bit and ratchet and then I do most everything else underneath with a long 1/4" extension.

Mark