[QUOTE=pmeger;411530 snip... it only leaks when the bathroom shower and sink fill up the bathroom grey tank. As soon as i empty the tank the leak stops.[/QUOTE]
From that description, it sounds like a drain connection at the top of the grey tank or a vent at the top of the grey tank or the top of the grey tank is cracked.
Sherm & Terry w/rescues Steve (std Poodle) & Eydie (min Schnauzer)
2015 Jay Flight 27RLS (Camped: 102 nights 2015, 90 nights 2016)
2006 Ford F350 6.0 PSD, Lariat, 4WD, CC, LB, SRW, auto., Camper pkg.