How to Replace the Fuel Filter in a 1991 Chevey Blazer S10
- 1). Place wheel chocks behind the passenger side wheels, and lift the driver side of the Blazer with a floor jack. Place jack stands under the frame, and lower the vehicle onto the jack stands. Supporting the truck with the jack stands in this manner prevents injuries that occur if the floor jack fails.
- 2). Remove the fuel filler cap, and turn the ignition key to the off position. This relieves some of the fuel pressure on the system, and prevents the fuel pump from starting when the filter is removed.
- 3). Locate the fuel filter on the driver side frame rail, just behind the front door. The filter is a cylindrical shaped part, about six inches long, that's in the fuel line on the inside of the frame rail.
- 4). Place a drain pan under the filter to catch any fuel that spills. Loosen the filter fittings by using a 21mm wrench to hold the filter while turning the flare-type nut on the line with a 16mm wrench. Remove both sides of the fuel line from the filter and drain it into the drain pan.
- 5). Check the rubber O-rings located on the fuel line ends for tears and nicks. Replace any O-ring seal that shows damage. These seals are available at your local auto parts store.
- 6). Insert the fuel lines into the ends of the new filter, and thread the flare-nuts into the filter by hand. Be careful not to cross-thread them and cause the need for replacement fuel lines. Tighten both lines with the 21mm and 16mm wrenches.
- 7). Raise the truck off the jack stands with the floor jack, and remove the stands from under the vehicle. Lower the Blazer to the ground. Reinstall the fuel filler cap.
- 8). Turn the ignition key to the "Run" position--and then back to the off position--three times to prime the new filter. Each time the key is turned to the "Run" position, the on-board computer turns the fuel pump on and opens the injectors to add fuel for starting. Start the engine and check for fuel leaks.