Freightliner FL70-FL80 Fuel Tanks

Frequently Asked Questions About Freightliner FL70-FL80 Fuel Tanks

What size fuel tanks fit the FL70 and FL80, and how do I know which capacity I need?

FL70 and FL80 models typically accommodate 50 to 150-gallon fuel tanks, with 100-gallon tanks being the most common replacement size. To determine your needs, check your door jamb sticker for original tank specifications, or measure your existing tank's dimensions (length x height x width). Consider your typical route distances and payload requirements - local delivery trucks often work well with 50-75 gallon tanks, while long-haul applications benefit from 100-150 gallon capacities.

Will these fuel tanks fit my specific year FL70 or FL80?

Most aftermarket fuel tanks fit FL70 and FL80 models from 1995 through 2007, but mounting brackets and strap configurations can vary by year. Models from 1995-1999 often use different mounting hardware than 2000-2007 versions. Always verify your truck's exact year and check if the tank includes the correct mounting brackets, or if you'll need to reuse your existing hardware. Some tanks are universal fit but require year-specific mounting kits sold separately.

Are these tanks made of steel or aluminum, and which material is better for my application?

Both steel and aluminum tanks are available for FL70-FL80 trucks. Aluminum tanks weigh 40-50% less than steel, improving fuel economy and payload capacity, while offering excellent corrosion resistance. Steel tanks cost 20-30% less upfront and provide better impact resistance but require regular maintenance to prevent rust. For trucks operating in northern climates with road salt exposure, aluminum is typically the better long-term investment.

What's involved in installing a replacement fuel tank, and can I do it myself?

Installation typically takes 2-4 hours and requires basic mechanical skills. You'll need to drain the existing tank, disconnect fuel lines and sending unit wiring, remove mounting straps, and reverse the process with the new tank. Critical steps include properly torquing mounting hardware (typically 35-45 ft-lbs), ensuring fuel line connections are secure, and transferring your sending unit if not included. Most DIY installers recommend having a helper for positioning the tank and having new fuel line clamps on hand.

Do these replacement tanks come with sending units, straps, and mounting hardware?

Tank packages vary significantly between manufacturers. Basic tanks often come bare, requiring you to transfer your existing sending unit, fuel pickup, and mounting straps. Complete kits include new sending units, mounting straps, and hardware but cost 30-50% more. Check product descriptions carefully - sending units alone can cost $75-150 if purchased separately. Most customers find complete kits worthwhile to avoid compatibility issues with old components.