[nub]

Make sure to check these once in a while to make sure that the tubes don't come off their place. If possible, clamp them somehow so that they don't come off. I had the same problem with a 1993 explorer V6 XLT. I still do check them once in a while since a few seconds of looking it over saves the inconvenience of having your vehicle stuck in the middle of the street.

I don't know if it was related but this happened to me right before I found out that my oil was leaking and the car ran low on oil, then the tubes came off their places.