How to Replace O-Rings on an AR EHA Valve

The EHA valve, also known as the "Electro Hydraulic Actuator", is mounted to the side of the fuel distributor. The valve is connected to the fuel distributor by two bolts and two o-rings. The o-rings prevent fuel from leaking between the valve and the distributor. Whenever fuel is detected leaking from between the two components, remove the valve from the distributor and replace the two o-rings. If the new o-rings do not fix the leak, replace the valve with a new EHA valve.

Instructions

1

Park the Mercedes in a safe area and open the hood. Turn the engine off and raise the hood up.

2

Remove the bolts from the air cleaner assembly inside of the engine compartment with a ratchet and a socket. Pull the air cleaner assembly out of the engine compartment and place it on the ground. The EHA valve can now be accessed directly below the air cleaner assembly. The EHA valve is the small black rectangular component that has an electrical connector plugged into the side of the valve. The valve itself is mounted to the side of the fuel distributor.

3

Place a drip pan on the ground directly below the EHA valve. Unplug the electrical connector that is plugged into the back of the valve with your fingers. Loosen and remove the two mounting bolts from the EHA valve with a ratchet and a socket. Pull the EHA valve loose from the side of the fuel distributor. Place the valve on a clean surface.

4

Pull the 2 green o-rings out of the 2 ports inside of the fuel distributor with your fingers. The o-rings are seated inside of the fuel distributor ports where the distributor connects to the EHA valve.

5

Insert the 2 new o-rings into the fuel distributor ports. Reconnect the EHA valve to the fuel distributor with the 2 mounting bolts. Tighten the mounting bolts down tight with the ratchet and socket.

6

Plug the electrical connector back into the rear of the valve. Check the valve for leaks before re-installing the air cleaner assembly. Turn the ignition key on for about 15 seconds and then crank the engine. Inspect the valve for any leaks. If no leaks are detected, turn the engine off and re-install the air cleaner assembly. If the valve is still leaking, replace the valve with a new EHA valve.