I have a 4" rubber boot Y connection of 3 -4" pvc pipes that I want to replace with a pcv y. Having a hard time wrapping my head around doing it, since all 3 pipes are not able to move or wiggle enough to create enough room to fit new y on the ends, and if I cut the pipes back, then will be too short for y to fit.

Can someone please walk me through this?

Thanks,

Tony

Hey Tony,
All you got to do is ask.
Lett's replace that old Neoprene Wye with a 4" PVC Hubless SXSXS Wye,(see image). Use 4" No-Hub Bands,(see image) to connect it up.
Can't find a 4" PVC S XSXS Hubless or Street Wye in your area? No problem!
Click on; White PVC sch40 plumbing fittings - PlumbingStore.com (http://www.plumbingstore.com/pvc.html#wye) You will see a list of fittings j7ust under the banner. Click on "wye". At over fifty bucks they aren't cheap but hey! It's your best shot.
Good luck and thanks for rating my answer. Tom

You can install a hubless cast iron wye for about $10.