OM603 leaking shutoff valve fuel not vacuum - PeachParts Mercedes-Benz Forum

Bio300TDTdriver · #1 06-22-2008, 11:56 AM

I've been reading up on shutoff valve leaks for over an hour. I'm pretty sure I have the correct O-ring, but I'm not sure how to remove the shutoff arm. Can I take the lever off and then unscrew it from the IP? The shut off valve was put on by my Indy about a year ago, but I don't think the arm(lever) has been touched. I thought I would take care of this while I had the intake off. Has anyone changed the O-ring behind the arm?

sixto · #2 06-22-2008, 12:11 PM

The arm is held on a necked part of the shaft by that bolt sitting vertically in the picture. Remove the nut with an 8mm wrench, extract the bolt then pull off the arm. That will expose a washer held by a circlip(?). Remove the circlip and washer which will expose the o-ring.

Sixto
87 300D

Bio300TDTdriver · #3 06-22-2008, 01:28 PM

Thank you. I hope I have the correct size O-ring in Viton.

sixto · #4 06-22-2008, 01:57 PM

Material shouldn't matter since that seal holds back engine oil, not fuel. If you have fuel leaking out of the shut-off lever shaft, you have major IP problems.

Sixto
87 300D

Bio300TDTdriver · #5 06-22-2008, 03:31 PM

Well I hope it is engine oil, not fuel. What kind of major IP problems? The kind where I need to ship it to CA and have it rebuilt?

sixto · #6 06-22-2008, 04:24 PM

Don't worry about it. If fuel were leaking out the shut-off lever shaft, I doubt the engine would run.

Sixto
87 300D

Bio300TDTdriver · #7 06-22-2008, 04:35 PM

Quote:

Originally Posted by sixto

Don't worry about it. If fuel were leaking out the shut-off lever shaft, I doubt the engine would run.

Sixto
87 300D

It was just oil. It seems like the smaller of the fuel filter o-rings is the correct size so I used that. I did have some play in that shaft. I hope that is normal.

Bio300TDTdriver · #8 06-22-2008, 09:45 PM

So what did I mess up? The stop lever was down before now it is up. So should I have the air cleaner off and the phone book ready when I start it?

See the first post for the before picture.

sixto · #9 06-22-2008, 09:54 PM

The normal position of the lever is up like in the second picture. It has to be up to start the engine. When you turn the key to glow, the key switch vents the shut-off actuator circuit so the lever pops up if it's down or stays up if it's up to allow fuel flow to start the engine. When you return the key to off, assuming the engine was running, the key switch applies a vacuum, so to speak, to the shut-off actuator circuit. Vacuum pulls the lever down. Vacuum is only needed until the engine shuts off but the circuit can hold a vacuum for many days.

If you didn't touch the vacuum actuator, there is no risk of a runaway engine. You can try a MityVac on the actuator to confirm the lever moves down under vacuum and pops up when vacuum is released.

The shut-off lever bolt fell off in my car and I ran the car for days, maybe weeks, with the shut-off lever hanging loosely on the shaft.

Sixto
87 300D

gsxr · #10 06-22-2008, 11:57 PM

Ditto what Sixto said. The new O-ring should cure the oil leak at the shaft. And the lever will move from one position to the other, depending on the position of the key, and availability of engine vacuum. Use a Mity-Vac to verify operation if you're concerned, but as long as the shutoff pod was not touched, there should not be a problem at all. (If the shutoff pod is replaced, the function should always be checked with a MityVac before starting the engine again!)

Bio300TDTdriver · #11 06-23-2008, 12:14 AM

I replaced the o-ring with a Viton one. I know it didn't need to be Viton, but I had one. It was the same size as the small fuel filter o-ring.

Car starts and stops as before. I'll keep an eye on the leaking shutoff valve to see if the new o-ring fixed the leak.