Author Topic: Fuel Filter // Water Separator  (Read 3896 times)

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Offline Dwight Quertermous

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Fuel Filter // Water Separator
« on: August 25, 2014, 06:34:04 AM »
I went to the yard yesterday to do some PM on the coach and work on some checklist items. I wanted to drain water from the secondary filter and water separator. I took a 16 ounce quart jar to drain the water into. When I opened the vent valve to drain the bowl, I thought that the liquid only visible in the bowl would come out, then I could tighten the vent drain plug, and move on to the next task. Well, not quite so. I filled the jar, and had to close the vent valve. I know that the filter is at a lower elevation than the fuel tank, and that this is due to keep the lines full of fuel. My question is how do I change the element and or drain the water from the canister and keep from siphoning excessive amounts of fuel.  If it is any consolation, it is a Fleetwood excursion on a Spartan chassis and the filter separator is in the back right nest to the hitch.
Best Regards
Dwight Quertermous
05 Fleetwood Excursion
CAT C-7 350 HP

Offline Brett Wolfe

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Re: Fuel Filter // Water Separator
« Reply #1 on: August 25, 2014, 07:37:04 AM »
Dwight,

First, I suspect this the the PRIMARY fuel filter/water separator-- the first one the fuel gets to from the fuel tank is the primary. Then the lift pump, then the secondary filter.  It has the course filter element (10-30 micron).  The secondary filter is has the fine filter element (2 micron).

My suggestion is to fit a ball valve on the inlet side of the primary fuel filter.  Not only does that keep fuel from running out of the filter housing when you change the filter, but it also makes a great anti-theft device-- won't get very far with fuel system shut off.

Brett
« Last Edit: August 25, 2014, 09:05:56 AM by Brett Wolfe »

Offline Dwight Quertermous

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Re: Fuel Filter // Water Separator
« Reply #2 on: August 25, 2014, 10:33:57 AM »
Thanks for the info Brett.... I will add the ball valve. Great Idea. One question though. If I forget to open the ball valve and start the coach, I am in essence sucking the system dry. Will this pose a problem and cause re-start problems as well?? Could there be damage to something because the vacuum or dead heading the fuel pump? The bottom of the canister is  only about 1/4" from the top of the hitch. I am going to fabricate and install a new mounting bracket with a brass ball valve as well. 
Best Regards
Dwight Quertermous
05 Fleetwood Excursion
CAT C-7 350 HP

Offline Brett Wolfe

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Re: Fuel Filter // Water Separator
« Reply #3 on: August 25, 2014, 11:28:52 AM »
Dwight,

No with the ball valve shut, it will not suck air (unless of course you have an air leak at the primary filter or line from primary filter to lift pump).

I really have no information on effect of closed ball valve if trying to start.  Never really considered it, but can not fathom that a "no start" situation or at most start and run for a few seconds would harm the fuel system.

But, if someone is trying to steal your rig, I think the risk would be worth it.  And the only time, other than in storage when you would close the valve is to change filters. 

I guess, to play it safe, you can use a nylon zip tie to secure the ball valve handle in the open position except when servicing the filter.

Offline Dwight Quertermous

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Re: Fuel Filter // Water Separator
« Reply #4 on: August 25, 2014, 11:37:35 AM »
Good point Brett - Thanks
Best Regards
Dwight Quertermous
05 Fleetwood Excursion
CAT C-7 350 HP