I just ordered an O-ring for my ICV. From what what I understand, there is 1 seal per ICV unit. I am also going to apply a gasket material to other leak-prone areas such as around the electrical connector. A previous thread (here) said the Military Standard number for an appropriate seal is 28775-219 (MS28775-219). Or it's AN6227-24. FYI.

I've been chasing down some problems and this is on the list of causes. My ICV appears to work perfectly well other than the suspected leak.

Anyone have any idea how big of a vacuum leak an ICV could cause?

 

I see aftermarket ICV valves on ebay for $20 to $35. I never tried one , but it might be a cheap alternative to rebuilding one with adhesive and orings.

 

I actually just put things back together after fixing my ICV. I'm really happy with how it went. The new O-ring fit perfectly snug. The old one was stiff and it broke when I flexed it. I put the ICV back together and then I applied air pressure, as well as vacuum, and found another leak. I was able to fix it by applying a high-quality sealant at the perimeter of the electrical connector. Sealant inside the connector itself was not necessary. After these 2 steps, the ICV was tight as can be. It seems to have fixed my problem. I'm going on a pretty long drive (60 miles) in a minute, so we'll see how it all holds up. Vacuum pressure is improved so far.

It turns out there is a second O-ring between the plastic piece which contains the electrical connector and the metal body of the ICV unit. It's a smaller O-ring which I did not replace. To anyone reading this and wanting to replace this one, you also have to remove the two large magnets inside the ICV, and then remove plastic piece with the electrical connector. Not sure what size this smaller O-ring is, though.

Jimbo, I saw those cheap ones you were talking about, but even a 34-year-old factory Bosch unit is hard to beat.

 

Agreed. If you have the time and patience.