Shut Off Valve

A shut off valve stops your engine from running once you switch off the ignition key. Once this part gets damaged, the engine may overheat, resulting in complete vehicle breakdown. Replace a busted shut off valve right away to prevent this problem and avoid higher repair charges in the future. Here are the tools you need and the steps in installing a new shut off valve for a diesel-powered Mercedes-Benz vehicle:

• Screwdriver
• 1/4-inch drive ratchet
• Spray paint can top
• Piece of wood
• Wheel stops and jack stands
• Safety glasses
• Two gaskets
• Vacuum pump

Step 1: Fit a spray paint can top over the turbo inlet to cut the air supply. Doing this will instantly shut down the engine so that you can work without risking your safety. For a non-turbo car, place a piece of wood over the intake manifold opening to stop the car. Disconnect the car's battery cable as well.

Step 2: Remove the vacuum hose and any other parts that is blocking your access to the shut off valve. Vacuum connections are very brittle, so be careful when taking them off. Use a screwdriver to gently pull the hose off.

Step 3: Detach the nut from the brake booster and remove it also from the other end. Next, remove all vacuum hoses connected to the transmission switchover valve. Unfasten the hose located on the side as well.

Step 4: Remove the ALDA line and the two bolts securing the switchover valve. Remember not to disconnect the linkage. Lay the valve over the oil filter housing.

Step 5: Take off the four screws securing the ALDA top cover plate to your injection pump. Next, use a 1/4-inch drive ratchet to remove the four bolts holding the valve to the pump.

Step 6: Connect the vacuum pump to the damaged shut off valve. Make sure you remove the retaining cover first. Apply vacuum to retract the valve's long arm so that you can pull it out easily. You may also compress the long arm using needle-nose pliers if the leaking valve can no longer hold any more vacuum. Doing this will help you gain additional clearance to remove the valve.

Step 7: Install the gaskets and fit the new shut off valve into the pump. Bolt the valve into place and apply vacuum to ensure it is working properly. Reassemble the parts you removed earlier and start the car. Run it for a few minutes before shutting it down to test the new shut off valve.

1. Secure your vehicle with wheel stops and jack stands before doing the installation.
2. Wear safety glasses to give your eyes full protection while working.