* Quick-disconnect fittings: These are the most common. They require a special tool, often called a fuel line disconnect tool or a fuel line quick disconnect pliers. These tools are designed to compress a retaining clip, allowing the line to be separated safely. You can find these at most auto parts stores. Improper tools can damage the fittings.
* Compression fittings (less common): These may use a clamp or a flare nut. For a clamp, you'd need a suitable pliers or clamp wrench to loosen the clamp. For a flare nut, you'll need a wrench that fits the nut.
* Bolted Connections (rare on fuel lines): If the line is bolted, you'll need the appropriate wrench or socket to remove the bolts.
Regardless of the connection type:
* Safety is paramount. Before working on any fuel lines, you *must* disconnect the negative battery terminal to prevent sparks.
* Work in a well-ventilated area. Fuel vapors are highly flammable.
* Have rags or absorbent material ready. Some fuel will likely spill.
* Safety glasses or goggles are essential.
* Gloves are recommended. Fuel can irritate skin.
In short: Start by visually inspecting the fuel line connection. Determine the type of fitting, then purchase the appropriate tool(s) from an auto parts store. If unsure, consult a repair manual specific to your 2004 Chevy Trailblazer. Attempting this without the correct tools and safety precautions is dangerous and can lead to injury or damage.
