How to Mount and Remove a Distributor Cap

Older automobiles use a distributor and cap to transfer an electrical impulse to each spark plug for igniting fuel in the combustion chamber. These are usually made of light plastic which can crack and accumulate build up that interferes with correct functioning. You should remove yours every time you service your car, inspect and mount a new one, if needed.

Difficulty: Moderate

Instructions

Things You'll Need:

• Maintenance manual
• Wrenches of various sizes
• Screwdrivers
• Socket set and driver
• Marking tape
• Marker
• Penetrating oil
• New distributor cap
• New rotor

1. Ensure the car engine is off, then remove the positive cable from the battery terminal.

2. Consult your maintenance manual for instructions on removal and replacement of your particular distributor cap, because they are all different.

3. Find the distributor by following the wires from the spark plugs. Get access to the cap by removing anything that is in the way, usually the air cleaner.

4. Leave the plug wires in place, or use a small piece of tape to mark each wire so you can replace them in the exact spot from which they came.

5. Remove the bolts, screws, or clips that attach the cap to the distributor body. Use whatever tool is indicated by the screws or bolts. Some are threaded into the distributor, and some are spring loaded J hook clamps that you only need push down and turn counter-clockwise a half-turn to release the cap.

6. Check underneath the cap for cracks and carbon. Replace the cap by transferring the plug wires to the same terminals on the new cap then replace the cap and retaining clips or screws.

Tips & Warnings

• Spray the screws or bolts holding the cap with some penetrating oil first. They can rust over time and seize to the distributor body. If you twist too hard, they may break causing your minor repair to become major.
• It's a good idea to replace the rotor underneath the cap while you have the cap off.
• Don't worry about not getting the cap back on in the right position. There is normally a lug or key-way on the distributor and a corresponding notch on the cap, so it's impossible to get it wrong.
• Ensure the hood of the car is properly supported and blocked open so it won't come down to hit or pinch you.
• Take care to get each plug wire back on the right terminal on the cap. If your car runs badly after this repair, recheck the placement of the wires.