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Iwillbeit · 04-03-2015, 09:08 AM

I am about to change the fuel filter and fuel water separator filter on my motorhome for the first time (by me) . Looks easy enough because they both look like a spin on oil filter. I believe my owner's manual says not to pre-full the filters because it has a self priming system. My question is. Is there anything I should be concerned about, or any special advise someone can share. Also will the fuel start draining when I remove the filter?

Randy W

Randy Williamson

tom chelbana · 04-03-2015, 10:30 AM

You will have some fuel loss when the old filter comes down. Put a little oil on the new fuel filter before putting on. You will need to cycle the key on and off as many as 5 or more times. Turn the key to the on position for 10 sec. and then turn off for 10 sec. Don't over tighten fuel filter only hand tight. Check with Spartan many chassis came with a secondary fuel filter that some people don't change and then have problems down the road.

YC1 · 04-03-2015, 10:39 AM

I have not been successful in NOT filling my filters. Doing one at a time does not help. Cycling the key just does not do the trick on my 08. May just be the design of the system or the layout of the hoses. I fire it up and in a couple of minutes it dies from lack of fuel. It is just too easy for me to fill one up. I keep a quart of fuel onboard just for that purpose.

If you have not taken the other filter off yet you could be in for a treat. Mine was undercoated along with lots of other things so it was stuck. I had to remove the mount and put it in a vice and use a large pipe wrench to get the filter off. No problems now of course. That was years ago.

stuhly · 04-03-2015, 10:54 AM

Save yourself some grief. Fill the filters. Be sure to keep it clean. I'm sure someone will jump in and tell you not to. If you ever airlock it you will understand why you fill them.

Iwillbeit · 04-03-2015, 12:22 PM

I want to thank everyone for their advice and ask one more question.
My coach is built of a Freightliner chassis. The fuel filter and water separator filter are next to each other. Do I have a third filter somewhere else?

Randy Williamson

Mr_D · 04-03-2015, 12:28 PM

They say not to prefill the filters because, if you do it wrong, you are adding unfiltered fuel to the engine which can plug or damage the injectors. However you CAN prefill them IF you only put the fuel in through the outside small holes since the fuel comes in through them and goes out the large middle hole. You can probably find a correct size/thread pipe nipple and thread it into the center hole. That will keep the unfiltered fuel from getting in while you fill the outside.
I always install mine dry as per the instructions.

Mr_D · 04-03-2015, 12:29 PM

Quote:

Originally Posted by stuhly

I'm sure someone will jump in and tell you not to.

And the reason for that is because the factory says not to do it!

Koop · 04-03-2015, 02:45 PM

I installed mine dry. I turned the key to on position, waited thirty seconds then turned it off. I repeated this one more time then started the engine. It fired right up, no problem. Why risk contaminating the fuel by pre-filling when it isn't necessary?

Coma · 04-03-2015, 02:51 PM

Do you have a rear start? If so, you can run the lift pump to fill the filters. Turn the switch to the rear position, front/off/rear. As you go from off to rear the lift pump will cycle. Do his until you hear the pump take pressure. Start will the filter furthest from the engine. Get the engine primed and running with that filter change. Do the one closest to the engine next. Repeat the process. Easy Peasey.

Dutch Star Don · 04-03-2015, 07:58 PM

I'm with YC1, I tried replacing them dry and couldn't get the coach started. I clean my hands, place my thumb over the center fill hole and fill the filter from the outer edges. This keeps from getting dirty fuel past the filter. My new coach has a primer,, so no more prefilling.

stuhly · 04-03-2015, 08:39 PM

You ever airlock one Mr D you will know why they should be prefilled. To each his own.

GreaTOne65 · 04-03-2015, 09:13 PM

Most new filters come with a plastic plug in the center hole, so filling one with fuel is not that dangerous. I myself, will not pre-fill, I prefer to change them, cycle the pump half a dozen times, and if it doesn't start, I crack two injector lines, never fails, fact is that's the way we always did it on the farm anyway.