How to Replace the Fuel Filter on a 1986 Mercedes-Benz 300E

The fuel system on the 1986 Mercedes Benz 300E comes equipped with a cylindrical fuel filter designed to keep fuel sediments and small particles out of the fuel injectors. If any of the particles and sediments get into the fuel injectors, they can clog the injectors up. The purpose of the filter is to trap the sediments before they reach the fuel injectors. Change the fuel filter between 60,000 and 75,000 miles to prevent the fuel filter from getting clogged up and releasing any sediments into the injectors.

Tools Used: Jack, Jack stand, 3/8-inch drive ratchet, Metric socket set, Drip pan, Metric open-end wrench set, New fuel filter

Replace the Fuel Filter

Park the 1986 Mercedes Benz 300E in a ventilated location so that the gas fumes can escape. Engage the parking brake to prevent the vehicle from rolling while it is on the jack stand.

Walk back to the rear of the 300E and unscrew the gas cap. This will prevent gas from spraying everywhere when the fuel lines are removed from the fuel filter by relieving pressure in the fuel system.

Jack up the right-rear of the car and place a jack stand under the designated jacking point. Then, slowly lower the vehicle onto the top of the stand. Leave the jack in the upright position as a extra safety precaution.

Locate the fuel filter protective cover in front of the right-rear axle. The fuel filter is mounted behind the cover that is directly in front of the right rear axle. Remove the cover by removing the small plastic nuts with the ratchet and a metric socket. The fuel filter can now be accessed. Lay the cover on the ground.

Position the drip pan underneath the fuel filter. Locate the fuel lines coming out of each end of the fuel filter. The top fuel line has a female hex-head fuel line nut and the bottom fuel line has a male fuel line hex-head nut. Remove the fuel lines by turning the hex-head nuts counterclockwise with a metric open-end wrench. Then, pull the fuel lines straight out of the fuel filter.

Pull the fuel filter out and place it in the drip pan. Then, position the new fuel filter into place and screw both of the fuel lines onto each end of the fuel filter. Hold the fuel filter with one hand while tightening the hex-head nuts on the fuel lines. Make sure that both fuel lines are tight.

Reinstall the protective cover back over the fuel filter. Screw the plastic nuts back on tight. Pull the drip pan out from under the car. Screw the gas cap back onto the tank.

Turn the ignition key to the "Accessory" position for five seconds and then turn it back to the "Off" position. Repeat this a total of three times to completely prime the new fuel filter with gas.

Crank the engine and inspect the new fuel filter for any signs of a gas leak. Then, turn the engine off.

Jack the rear of the car back up and remove the jack stand. Then, lower the car back to the ground and slide the jack out.

Tips & Warnings

The fuel filter is designed to fit onto the fuel lines one way only. This prevents the fuel filter from being installed backwards.

Do not smoke or use any type of open flames around gas. Wear protective glasses around gas.

Always refer to local and state laws that pertain to the discarding of used gas and used fuel filters.

Post a Comment