1997 Oldsmobile Bravada Q&A
1997 Oldsmobile Bravada Question: what is causing the bottom of the gas tank to suck inward?
I have seen both vent valve failures and canisters saturated cause the same thing.The purge valve pulls a vacuum on the tank at a predetermined time and after it's done the vent valve will release the vacuum from the tank,yours is not releasing this vacuum. - bmdouble
Should have evap trouble codes, is the check engine light on? Vacuum when removing gas cap and does the tank pop back out? - pushrod
did you just install a new gas cap? or ck #1 suggestion and scan evap codes - globalhelper