Bypass the rear heater core pipes! The two lines do go to the rear heater core. Mine was leaking like about 1.5 gal in a half hour of driving right where the exhaust pipe exits. I never use it, so I decided to bypass it altogether. I spent some time and found the same heater core for the front cabin is used across a bunch of vehicles including the pick ups. ( no rear heater, right?) Same part number on GM website. So the quick connect entrance/exit tube is the same. Irt took some driving around to finally get the correct part. So I just cut off the hose, added a double barbed connector, added six inches 5/8" heater hose and replaced the "quick connect" witha Dorman part number 800-409. slips right in and almost loks like factory work. I don't know why people don't put the part numbers down. Would have saved me time on research. One note is they do NOT look anything alike. The original "T" one had 2 white plastic clips that have to be depredssed to slide the connector past the rib on the each of the 3 pipes. The new ones require the split round "tool" to remove, have no visable clips on the outside and is black. Now I could have just cut the hoses, added 6 inches of hose and secured with hose clamps, but it is extreemly tight in that area and being able to just push it straight on was quicker and easier. Just cost a couple of bucks for the convenience.