Do it yourself and save
Idle the truck briefly to fully prime the system, and then shut it off. Fill the new primary filter to the top with clean fuel, making sure to lube the gasket as the filter maker recommends. Remove the old primary filter and immediately install the new one.
Idle the truck until it runs smoothly, an indicator that all air has been expelled from the system, then shut it off. Repeat the entire process for the secondary filter.
Some large filter/separators with plexiglass housings allow you to drain the housing, replace the filter and then remove a cap for full priming with fresh fuel prior to starting the truck.
Some engines, like later Cummins ISX models, include a priming pump. All you need to do is open a bleed port and run the pump until fresh fuel comes out. Consult your engine manual for instructions.
Cleaning connections and cables
Your cost: $10
Shop cost: $80 – $100
Time: 1 hour
Litosky says one simple task is cleaning connections and inspecting and replacing battery cables and ground straps. Special battery terminal cleaners are inexpensive, and other connections can be cleaned with sandpaper or steel wool. The engine ECM has its own voltage supply, and checking that wiring staves off many problems. Make sure to disconnect battery connections prior to doing electrical work.
Inspecting cooling system
Your cost: $2.50
Shop cost: $20
Time: 1⁄4 hour
To check your system, buy test strips and measure antifreeze concentration and the level of anti-corrosion additives. Adding SCAs (supplemental coolant additives) when necessary or using extended life antifreeze cost little and will prevent expensive engine repairs such as redoing cylinder kits because of liner pitting from corrosion.