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Thread: Terminator throttle body o-ring?

  1. #1

    Default Terminator throttle body o-ring?

    Is the Terminator throttle body supposed to have an o-ring between the back of the TPS sensor and the boss that the primary throttle shaft fits through? I've been chasing a vacuum leak. Did a smoke test and found small leaks around linkage side of both throttle shafts. Found a bigger leak coming out from behind the TPS sensor. Removed the TPS and there was no o-ring. Was told by a knowledgeable person that it's supposed to have an o-ring. Holley Tech said that an o-ring does NOT go there. There's a nice chamfer like it's made for an o-ring. But mine didn't have one. What gives?

  2. #2


    I did a smoke test on mine long ago also and found no o-ring. The way the throttle body is machined at the bottom it wouldn't matter if there were, as it wouldn't seal. The TPS on GM models does have the o-ring, as you're thinking. The small amount of leak seen with the smoke won't matter enough to cause any issues.

  3. #3


    The primary source of my air/vacuum leak was the IAC. It wasn't closing all the way.

    However, I tried a 3/8" x 1/16" o-ring and a 3/8" x 3/32" o-ring between the TPS and the throttle shaft boss. The 3/32" cross-section o-ring completely sealed the leakage past the throttle shaft. Probably not a bad idea. Can't hurt. It does work.

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