Here is the use for the Bypass copied and pasted from the manual. Essentially, as I understand it, it simply allows the gray to run out by gravity. "Dripping Gray" is acceptable in some National Forests and BLM lands in the West. I have had forest officials tell me out there that it is helpful because of the drought. It also allows you to drain your gray tank without running the pump.
Using the Gray Water Bypass
Caution: To avoid the risk or the
pump running dry, do NOT turn
the pump on to use the gray water
bypass, as the gray water bypass
relies on gravity.
!
1. Make sure that the black and gray
water RV dump valves are closed.
2. Point the nozzle upward and remove
the nozzle cap.
3. Insert the nozzle into the sewer
connection and give it a half-turn to
lock the nozzle into the connection.
Note: The nozzle has a 4 in. (10.2 cm)
and a 3 in. (7.6 cm) threaded
section that adapts to 4 in.
(10.2 cm) and 3 in. (7.6 cm)
threaded sewer pipes.
Note: If the sewer pipe is non-threaded,
use the tapered press-fit section
on the nozzle to connect to the
sewer.
4. Open the gray water valve to let the
gray water drain into the sewer.
Obviously, with the kink many are experiencing she be a no-go until the kink is removed. I carry a 15 foot garden hose (called a "remnant hose at Home Depot, Lowes, etc.) and hook it up the standard "emergency drain" on my rig. In case a kernel of corn or something goes down the sink, I suspect that little bypass tubing on the pump might be vulnerable to being clogged. Works good for me on this and previous units.
MODIFICATION: I posted this seconds after TomHanlon made the same post. Sorry for the same info twice.
Paul