Safety Warning

DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.

2001 GMC C3500 HD 6.5 F, AutomaticFACTORY OEM SERVICE PROCEDURE

Installation Procedure

Insert a new O-ring seal.

NOTE: Do not fold or twist the strainer when installing the sending unit. This action restricts fuel flow.

Install the sending unit assembly into the fuel tank.

Fig 1: Fuel Sender Seal Ring

Courtesy of GENERAL MOTORS CORP.

Install the hoses onto the sender assembly.

Fig 2: Fuel Sender Unit Cam Lock

Courtesy of GENERAL MOTORS CORP.

Install the cam lock assembly.
Turn the cam lock clockwise in order to lock.
Install the fuel tank. Refer to Fuel Tank Replacement (Extended Cab Side Tank) or Fuel Tank Replacement (Cab and Chassis Rear Tank) or Fuel Tank Replacement (Cab and Chassis Side Tank) .
Connect the negative battery cable.
Check the system for leaks.
1. Turn ON the ignition switch for 2 seconds. The scan tool can be used to activate the fuel pump to check for fuel system leaks.
2. Turn OFF the ignition switch for 10 seconds.
3. Again, turn the ignition switch to the ON position.
4. Check for fuel leaks.

Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.

Shop Manual-Ready Tools Compare Repair Quote Quote Shield Pro

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.
• Brakes feel soft, pull hard to one side, or make grinding noises.
• The engine overheats, stalls repeatedly, or misfires under load.
• You are missing required tools, torque specs, or safe lifting equipment.
• You are not confident in the next step or safety outcome.

Rather have a pro handle this?

A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.

Comes to youSame-day available12-month warranty

Get a Free Quote

No obligation. See pricing before you book.