How to Keep Moisture Out of Your Distributor Cap

If there is moisture in your distributor cap you’re going to have problems starting your car. Fortunately, there are ways to keep the inside of the distributor cap dry.

Step 1 - Access

Remove the coil wire from the distributor cap and follow this with the spark plug wires, marking which wire goes where on the cap. If the distributor cap screws down, remove the screws. If it’s held in place by clips, use the screwdriver to open them. Take off the distributor cap.

Step 2 - Cleaning and Seal

Using a clean, dry rag, wipe out the inside of the distributor cap and leave it in a warm area to dry out. Pry off the old seal at the bottom of the distributor cap and also clean the distributor itself.

Step 3 - Keeping Moisture Out

Replace the old seal with a new one; you’ll probably find that the old one is cracked and brittle. Replace the distributor cap. For extra protection run a bead of silicon caulk around the base of the cap. Replace all the wires, taking care to have all the wires in the right places. Try to start the car; it should turn over with no problem.