vent goes to defrost on long hills
#11
#12
They look fine to me, so do the ones that connect to the vacuum switch on top of the transfer case, 4x4 works great, and this problem only happens when i'm on a long hill, it's 5 speed so i usually just let it put up the hills in 5th gear. so if it only happens then i'm not going to worry about it. i found another forum that said it could also be bad pcv valve or failed check valves, mine is a 98, do you know where all of the check valves are?