I am new to diesel trucks and have a few easy questions so please bare with me. Is the fuel/water seperator i see right under the hood the only fuel filter in the line? Also there seems to be a blow off valve at the bottom of the fuel/water seperator. How do i go about blowing off the fuel/water seperator. After how many miles should i change the fuel/water seperator?

thanks in advance

Jeff

 

Hi Jeff,

That is the only fuel/water seperator/filter on the system. I change mine every second or third oil change... say every 10K miles is good.
Use care when you remove it, you don't want the fuel heater to turn and come off while you're doing this. It is the metal disk that the filter threads onto. Also remove the electrical plug as well.

The 'valve' you describe is the fuel drain valve. It allows you to drain off a bit of fuel and any water that it may have had settle in it. Just lift the little round tab upward and drain off some fuel into a clear glass jar. Check for signs of water. Always be sure to tug that little valve down and in place when your done, or you could have slow trickle of fuel leakage as you drive if it doesn't reseat properly.
I usually drain off a bit every 3rd or 4th tank of fuel.
I would suggest that your add a good healthy dose of fuel conditioner to the tank as well.
You can use any of the major names...Stanadyne Performance Formula, Howes Meaner Power Cleaner, Lubrication Engineers, Power Service etc.
First time you use it, go with at least double or even triple the recommended dosage... you won't do any harm. Our pumps are lubricated and cooled by fuel only so the additive helps with lubrication of the internal pump parts.

I hope that helps and, if I've overlooked anything don't hesitate to ask...

bob....

 

After i replace the fuel filter do i need to prime it in any way?


thanks


jeff

 

Its best to prefill the filter before installation. Unless you love cranking the holy crap out of your truck. Be sure the old O-ring on the threaded filter head stub is replaced, they tend to stay in place unless you reach up there and pull it off.

 

I unplug the filter, unscrew the filter and make sure the O-ring comes off with it. I take the plastic valve off the old filter and switch the old, small O-ring out with the new one. I fill the filter straight from a bottle of fuel conditioner and put the new, large O-ring around the threaded hole. I screw the new filter in place and plug the wires back in. I give the lever on the lift pump a few pushes and she cranks right up. If I don't pump the lift pump, she usually just gives a slight hiccup anyway. If you do get some air that won't clear the injectors and she runs a bit ruff, give the injectors a slight, crack open with the engine running. It'll start purring again.

 

Where are the wires located that you unplug? I can't see any wires right beside my fuel filter. Do you have to unplug these wires?


thanks
jeff

 

They should run from the drain valve at the bottom. Two wires. These are for the water in fuel sensor.