SOV O-Ring 1997 E-300D - PeachParts Mercedes-Benz Forum

rodm · #1 07-05-2010, 02:29 PM

I just changed the o-ring on my SOV as it appeared to have a slight leak. Many months back I had a problem with engine run on posted about it but then decided not to change it. My problem is I am not sure if the o-ring I used is correct. As now when I start the engine diesel is gushing out around the SOV. Many posts list the SOV o-ring as being 2.5mm thick X 12.0 mm ID. I did replace mine with that size in Viton as I use 100% bio. However the o-ring I originally removed was 4.5mm thick X 12.0 ID. It was in good condition but slighty harder than the new one. In addition the top was flat as a car tire as opposed to the shape of a tire tube. Any suggestions anyone. Idid not buy the new o-ring from an auto parts shop but from a large local hydraulic shop.

RodM

KarTek · #2 07-05-2010, 07:26 PM

I believe the 2.5mm x 12 is correct. There are at least 2 grades of Viton: a soft one and a harder one. The ones I used on my car are the harder variety. That may account for the leak.

You also need to make sure you don't pinch the ring when you re-insert the SOV.

rodm · #3 07-06-2010, 05:29 PM

Pulled the SOV off and the oring is torn so I guess thats why it leaked. Cant figure out what I did wrong on the installation I do know I could not get the SOV to mate to the surface that its bolted to had to tighten to two torx bolts to get it to seat. Will try again with a new oring.
RodM

rodm · #4 07-09-2010, 11:46 AM

Replaced new oring today and same problem.....LEAK. Luckily I bought a replacement oring so no trip back to the store. However I have a question maybe I am doing something wrong. There is a lip on the part the oring goes on to and I have been putting the oring on that lip. Is this correct or do I have to put the oring just in front of the lip. It is quite snug when it is placed in front of the lip. I cant find any pictures in the parts section of FASTLANE that shows wher the oring goes any suggestions.???

THANKS

leathermang · #5 07-09-2010, 11:54 AM

Your car is too new for me to help on..
but
What is an SOV ?

rodm · #6 07-09-2010, 01:59 PM

SOV = Shut Off Valve also known as a shut off solenoid.

Rod

KarTek · #7 07-09-2010, 07:20 PM

I'm not sure what lip you're talking about but the O ring rolls all the way down to the bottom of the round protrusion that goes into the pump body.

You should be able to see a bevel on the opening in the pump body and this is where the ring seals.

rodm · #8 07-10-2010, 03:08 PM

I am truly frustrated now and out of orings. Evan I did send TMALLISON a private email ref this problem and he responded the oring goes all the way to the end of the nipple on the SOV. Which I did again resulting in the leak for the THIRD time. To explain the SOV has a nipple which, goes into the IP and to which the oring is placed on. That nipple has a lip or it increases in size just next to the body of the SOV. THREE times now I have placed the oring on the lip and 3 X now its leaked. I have asked if the oring goes in front of the lip and NOT ON IT. When the oring is placed in front of the lip or ridge or wider portion of the nipple it seals flush against the IP. However once it is placed on that lip no amount of twisting , pushing allows it to seal against the IP as result I slowly tighten the 2 torx screws equally finally torquing them to 14 lf lbs. and that time I have a perfect seal VISUALLY until engine is started. I will now try to find a new oring BUT this time not put it on the lip..... Any words of wisdom anyone. PS my friend across the ST. on leave from assembling the new Boeing in SC has been watching me and is just as confused.

KarTek · #9 07-10-2010, 04:31 PM

Picture is worth 1000 words...

rodm · #10 07-10-2010, 04:50 PM

Wow It does go in front of the @#$%*&^ NIPPLE. Wow i guess the 4 one the right spot when I find it. THANKS A BUNCH

Rod

rodm · #11 07-10-2010, 05:02 PM

Was so excited to see the answer that my post made no sense. What I was trying to say is that the fourth one once I find it will now go in front of the lip.

Rod