1999 GMC Sierra 1500 Pickup Owner's Manual - Page 23

Rear Seats Rear Folding Seat (Extended Cab Models) ' ' - I PO491 Theextendedcabmayhavearearfoldingseatwhichcanbefoldeddown formoreseatingspace. To usetheseat,pulltheentireseatforwarduntil it isflat.Pullforwardon the, RELEASE lever,undertheright-handsideoftheseatcushion.Pushthe seatbackrearwarduntilitlatches. After pushing the seatback upright into position, pull the seatback forward to makesureitislocked. Rear Seat (Four Door Models) You can adjust the seat by sliding the adjuster lever at the front of the seat toward the 'door to unlock it. Slide the seat to where yau want it. Then releasetheleverand try to move the seat with your body, to makesure the seat is lockedintoplace. 1-9