Oil Filler Cap Mod


We all get tired of the oil film/leak on top of our 4.0 Jeep aluminum valve covers. Many times the biggest culprit is the loose fitting oil filler cap. Here’s a real easy fix:

  1. Remove the plastic oil filler cap and wrestle the original rubber gasket from it using a small pick or screwdriver.
  2. Make a duplicate of the gasket out of an old bicycle inner tube using scissors and a knife or razor blade.
  3. Install the duplicate on the cap first, and then the original over top of it.

It will be a tight fit on the valve cover the first time, and may require some persuasion with a pair of pliers, but will get easier with time.


Revised 1-31-2016

4 thoughts on “Oil Filler Cap Mod”

  1. My oil cap gasket is not pliable AT ALL! I don’t see any way to get it past the locking tabs on the cap without damaging it. Suggestion appreciated.

  2. I used some sheet viton to cut my own gasket, 1/8 inch thick. works fine and Viton is highly oil and heat resistant.

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