How to Change the Fuel Pump on a 1999 Chevy Blazer ZR2
The first Chevrolet S-10 Blazer was produced in 1983. The 1999 S-10 Blazer offered an option for a ZR2 package, based on a two-door 1999 S-10 Blazer, with four-wheel drive and many added cosmetic amenities. The fuel tank on the 1999 Blazer ZR2 runs parallel to the driver's-side frame rail and sits just in front of the driver's-side rear wheel well. The fuel pump for the 1999 Blazer ZR2 is located inside the fuel tank and only accessible by dropping the fuel tank from the truck.
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Things You'll Need
- 3/8-inch drive ratchet and socket set, with at least 4-inch extension
- 1/4-inch drive ratchet and socket set, with 6-inch extension
- 2-ton or greater capacity floor jack
- 2 jack stands
- 2 vehicle ramps (replaces jack stands if available)
- Length of wood, 1-by-4-by-12 inches
- Large funnel
- 5-gallon or larger capacity gas can
Instructions
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Removal
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1
Raise the rear of the Blazer by placing a 2-ton jack underneath the rear axle housing. Place jack stands beneath either end of the axle housing, just inside the rear wheels. If you are using vehicle ramps to raise the rear of the S-10 Blazer in the air, you are eliminating the need for jack stands.
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2
Lie beneath the rear bumper of the SUV and slide your body into position, where you can physically access the bottom of the fuel tank and the fuel tank straps. Set the jack beneath the fuel tank and place a length of wood on top of the jack, between the jack and the fuel tank. Lift the jack until the wooden platform rests against the bottom of the fuel tank, between the two fuel tank straps. Do not push on the bottom of the fuel tank with the jack or platform. Do not attempt to hold the tank up solely with the head of the jack, or you can puncture the tank.
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3
Remove the fuel tank strap bolts, using a 3/8-inch drive ratchet and socket, with a 4-inch extension for leverage. Remove the fuel tank filler hose and vapor return hose from the outside of the tank, by removing the hose clamps with a 1/4-inch drive ratchet and socket and a 6-inch extension for maneuverability. Slide the metal portion of both the filler neck and the vapor return tube out of the rubber hose that is wrapped around the tubes.
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4
Lower the fuel tank halfway between the bottom of the truck and the ground, or until you can physically access the top of the fuel tank. Remove the small fuel tank hoses from the top of the fuel pump assembly, using a 1/4-inch drive ratchet, socket and extension to remove the miniature hose clamps. Pull the small hoses free of the pump once the clamps are removed. Remove the electrical connector from the top of the fuel pump assembly by squeezing the plastic lock tab between your thumb and forefinger. Pull the connector free of the pump while simultaneously squeezing the locking tab into the open position.
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5
Lower the fuel tank completely to the ground, on top of a large piece of cardboard. Resting the tank on a piece of cardboard will reduce the chance of electrostatic buildup between the tank and the ground. Static electricity can ignite fuel vapors. Slide the cardboard out from the rear of the truck, keeping the fuel tank on the cardboard.
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6
Place a flat-head screwdriver tip against one of the upward-protruding lock ring tabs. The lock ring is the metal ring that locks the fuel pump into the top of the fuel tank. Tap the handle of the screwdriver so that the lock ring spins counterclockwise. Spin the lock ring until it pops upward and free of the fuel tank. Remove the fuel pump from the fuel tank by pulling it straight up and out of the tank, twisting the pump to clear the fuel tank level float clear of the tank lip. Set the old fuel pump in a drain pan.
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7
Drain the fuel tank into one or two gas cans, using a large funnel. Flip the fuel tank upside down so that the fuel in the tank pours into the funnel. Draining the fuel tank will make installation of the new pump and reinstalling the fuel tank much easier. Not draining the fuel can make balancing the tank nearly impossible while trying to reinstall the tank, as the fuel swishes back and forth inside the tank and tips it.
Installation
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8
Set the new pump into the top of the fuel tank by hand, so that the hose connections on the pump and the electrical connector are facing in the proper direction for reinstalling the tank. Set a new fuel tank lock ring on top of the fuel pump. Push the lock ring down while simultaneously turning the ring clockwise, until it begins to grab beneath the fuel tank lip. Lock the fuel tank lock ring in place using a hammer and flat-head screwdriver to tap the ring clockwise, until it locks the fuel pump in place.
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9
Slide the fuel tank beneath the Blazer and align the tank beneath the installation point on the truck. When sliding the fuel tank, it is important to keep the tank on a piece of cardboard, as electrostatic charge can ignite fuel vapors that are escaping from the exposed fuel tank.
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10
Set a length of wood on a jack and position the fuel tank on top of the piece of wood. Do not attempt to lift the fuel tank solely on the head of the jack, as you can puncture the fuel tank. Set the fuel tank on top of the jack and wooden platform, making sure the piece of wood lines up directly in the middle of the tank. Aligning the piece of wood in the middle of the tank will ensure that you have clearance to reinstall the fuel tank straps.
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11
Raise the jack with one hand while guiding the fuel tank into place with your other hand. Lift the tank until it sits halfway between the ground and the bottom of the truck. Install the small fuel hoses onto the new fuel pump, tightening the hose clamps with a 1/4-inch drive ratchet and socket with an extension for added leverage. Install the electrical connector onto the new fuel pump by simply pushing the connector into the pump socket, until the connector snaps into place.
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12
Lift the fuel tank up until it seats against the bottom of the Blazer. Do not push the bottom of the tank inward or you can break the seams on the fuel tank. Simply lift the tank until it touches the bottom of the truck. Bend the fuel tank straps around the fuel tank and align the straps with the strap mount bolt holes. Insert the fuel tank mounting bolt through the tank strap and into the bolt hole, and start the bolt by hand a couple of turns. Reinstall the second tank strap in the same manner. Tighten the strap bolts up with a 3/8-inch drive ratchet and socket. The bolts should be tightened to between 60 and 80 foot-pounds of torque to properly secure the fuel tank.
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13
Add no less than 3 gallons of fuel into the fuel tank. Turn the ignition key to the "II," or accessories position, but do not turn the engine over. Turn the key back off. Repeat this process until you have turned the key to the accessories position at least three times. This procedure activates the new fuel pump, as well as primes the fuel lines and the fuel injectors with pressure enough to start the Blazer. Start the Blazer to ensure that you have made a proper connection with the new fuel pump.
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14
Lower the Blazer only after you have double-checked your fuel tank strap torque. Improper torque can cause the fuel tank bolt to jar loose over time.
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1
Tips & Warnings
When replacing the fuel tank, it is always a good idea to replace the fuel filter. The 1999 Chevy S-10 Blazer ZR2 has what is known as an in-line filter. This means that the filter is outside of the fuel tank and sits between the tank and the engine. The '99 Blazer fuel filter is on the driver's side, parallel to the driver's-side chassis rails.
This entire project involves working with gasoline. See Resources for information on working with gasoline.
If you have any doubt about your ability to complete this project in a safe manner, do not attempt it.
Gasoline is a highly flammable substance in both liquid and gas forms. Keep this entire project away from open flame, excess heat, spark, static electrical charge and cigarette smoking.
References
Resources
- Photo Credit Comstock/Comstock/Getty Images
