The glow plugs in a tractor work the same as glow plugs in any diesel engine. However, their exact location may differ according to the tractor. Because engine size and design ultimately determine where the glow plugs are fitted, you may need the particular tractor's service manual to help you locate the plugs.
Remove the glow plug wires running to one of the cylinders. While all of the glow plugs should be replaced, you should work on only one plug at a time. It generally does not matter which plug you start with. To remove the plug wire, pull up on it. You may need to twist or rotate it back and forth gently and pull up on it at the same time to remove it.
Connect the glow plug socket and socket extension together. Then, connect the extension to the socket wrench. Slide the glow plug socket down into the plug well (underneath where the the plug wire was that you removed from the engine). Fit the socket over the plug and turn it counterclockwise to remove it. Pull the plug out of the engine. Remove the plug from the socket and insert a new plug.
Slide the socket back down into the engine and thread the plug. Be careful when threading. You do not want to cross-thread the plug. Make sure that the plug threads easily for at least 3 turns. Tighten the plug and attach the glow plug wire. Repeat steps 1-8 for all glow plugs on the engine. For each plug wire, there is a glow plug underneath it.
