Thread: Vacuum Leak

I got one at my brake booster, turns out it was a split check valve grommet. I got a replacement, and got it into place on the sensor. The question is, now. how do I get the skinny part into the hole on the booster? I can't get it to fit.

Is the new part and old part diameter the same for that end? Barring that I sometimes need to lube that fitting up to get it to slip into the booster.