How to Change the Fuel Filter on a 1999 Blazerby Gregory Crews
The 1999 Chevrolet Blazer uses an in-line fuel filter. This means the fuel line is separated between the gas tank and the engine by a filter, which prevents impurities from getting into the engine. A strainer in your fuel tank picks out the larger pieces of junk and sediment, while the fuel filter traps the smaller particles. A Blazer with a clogged fuel filter will have poor acceleration and possibly stall. Changing the fuel filter will improve the gas mileage.
Park the truck on a flat, level surface. Set the parking brake.
Crawl under the truck and locate the fuel lines coming out of the fuel tank. Trace the fuel lines to the fuel filter, which is along the frame rail by the driver-side door.
Pull the quick-disconnect fitting off the outlet side with your hands. The quick-disconnect is equipped with a locking tab that can be pulled up. This will allow the fitting to slide off the filter piping.
Hold the larger nut on the inlet side of the filter with a 21 mm open-end wrench. Turn the smaller nut counterclockwise until you can pull the fuel line out with your fingers.
Slide the filter out and away from the plastic mounting bracket. There is no need to remove the bracket.
Position the new filter next to the plastic mounting bracket. Ensure that the arrow is pointing toward the front of the truck. The arrow designates the direction the fuel flows.
Push the outlet line onto the filter. The quick-disconnect will lock when pushed far enough onto the filter piping.
Push the inlet line onto the filter. Thread the smaller nut by hand. Secure it by holding the larger nut with a 21 mm wrench and tightening the smaller nut with a 16 mm wrench.
Start the truck and allow it to idle for five minutes. Check for any leaks around the filter.
- Auto Media: Fuel Filter Tutorial
- "Chevrolet S-10 & GMC Sonoma Pick-ups Haynes Repair Manual for 1994 thru 2004. Includes 1995 thru 2004 S-10 Blazer & GMC Jimmy, GMC Envoy 1998 thru 2001 and 1996 thru 2001 Oldsmobile Bravada & Isuzu Hombre"; John Haynes; 2004
- Pull the fuel pump fuse in the fuse panel to isolate the fuel pump and relieve pressure in the fuel line. Pull the fuse and allow the truck to run until it stalls. You can also allow the truck to sit for a few hours, which will help to alleviate pressure in the fuel line.
Things You'll Need
- 21 mm line wrench
- 16 mm line wrench
- New fuel filter
- Gasoline is highly toxic and flammable. Use caution when working around gasoline.
Gregory Crews has been in the film industry for three years and has appeared in more than 38 major motion pictures and 16 television shows. He also writes detailed automotive tutorials. His expertise in the automotive industry has given him the skills to write detailed technical instructional articles.