Hello everyone,

Until a couple days ago, I thought that all OM603 engine mounted vacuum pumps with the four torx screws on the front cover had sealed bearings on the cam drive. This sealed design prevents ball bearings from entering the timing chain cavity in the unlikely event of pump failure.

Please examine the pictures in this thread. There is NO way to visually identify whether or not your "new style" vacuum pump has the sealed bearings by looking at it from the outside unless it has the latest Mercedes part number (000-230-31-65) on it. However, if you buy an OEM Pierburg pump instead of OE Mercedes, the part number will be ground off.

Below are pictures of the original (semi-exposed ball bearings) vacuum pump:

Attached Thumbnails

     

Here's what the semi-new style pump looks like. Note the four torx screws on the front cover, but notice how the ball bearings at the cam drive are still semi-exposed - just like on the old original style pumps.

Attached Thumbnails

     

Here is the latest style pump. It has four torx screws on the front cover, but notice how the ball bearings at the cam drive are NOT exposed.

Attached Thumbnails

     

Lastly, here's a close up picture of the cam drive. The first picture is what you'll find on the original and "semi new" pumps. The second picture is from the latest version.

Attached Thumbnails

   

I just had a "new" pump put on this summer. Thanks for the heads up.

Chris

__________________
1987 300TD 309, xxx 2.8.2014 10,000 mile OCI


Be careful of the toes you step on today, as they may be connected to the ass you have to kiss tomorrow. anonymous

“Be who you are and say what you feel, because those who mind don’t matter, and those who matter won’t mind.” Dr. Seuss

That's really not good news.

The criteria using the Torx screws on the cover as evidence of the new design is clearly in error.

About the only certainty is to remove the cover and take a look to see what you have............

Can the cover be easily removed and reinstalled without removal of the pump?

I wouldn't try to remove the front cover. Even if you remove the torx screws, it's crimped on tight around the entire edge.

Is there any other way to verify which pump is installed?

This does not change the fact that if you have one without any torx screws in the front plate then you have the old/bad design, right?

-Jim

__________________
1995 S350D, Green with black leather interior.
Bought January 2008 w/ 233,xxx miles.
I did 22,000 miles during the first year of ownership.

correct

__________________
Current:
05 E320 CDI
07 GL320 CDI
08 Sprinter
05 Dodge Cummins
01 Dodge Cummins

Previous
2004 E55 AMG
2002 C32 AMG (#2)
1995 E300
1978 300D
1987 300D
2002 C32 AMG(blown motor :[
1981 300SD
1983 300SD
1987 300SDL
2002 Jetta TDI
1996 S420
1995 S500
1993 190E 2.6
1992 190E 2.3
1985 190E 2.3 5-Speed

none that i can think of, youll have to remove the entire pump to see if it has exposed ball bearings or not.

__________________
Current:
05 E320 CDI
07 GL320 CDI
08 Sprinter
05 Dodge Cummins
01 Dodge Cummins

Previous
2004 E55 AMG
2002 C32 AMG (#2)
1995 E300
1978 300D
1987 300D
2002 C32 AMG(blown motor :[
1981 300SD
1983 300SD
1987 300SDL
2002 Jetta TDI
1996 S420
1995 S500
1993 190E 2.6
1992 190E 2.3
1985 190E 2.3 5-Speed

I have the very old one. This is good timing for me. I'll be purchasing/installing the NEW new one in the near future.

-Jim

__________________
1995 S350D, Green with black leather interior.
Bought January 2008 w/ 233,xxx miles.
I did 22,000 miles during the first year of ownership.

You just might be able to construct your own retention plate for the open bearing. Might be worth a try.

Great information, Aaron - thanks for sharing.

If the part number is ground off, there's no way to tell without removing the pump. Attempting any kind of Rube Goldberg patch to the old pumps would not be wise, IMO, since failure could take out the timing chain and cause serious damage.

__________________
Dave
Boise, ID
Check out my website photos, documents, and movies!

I cannot see any difference between the "semi-new" and old style vacuum pumps except for the 4 torx screws on the front cover. Since the front cover is crimped on tight around the edge and cannot be removed, then what is the purpose of the 4 torx screws? Anybody knows when the "semi-new" pumps become available and when it was replaced by the new style pump?