The M-11 engine in my 1997 U-320 was running perfectly until I refueled today. I fueled at a station near my home where I've bought diesel for my pickup often, and they sell a fair amount of diesel. Anyway, leaving the station required brisk acceleration for a proper merge, and that's when the trouble started. It felt like the transmission was downshifting and upshifting rapidly back and forth a couple of times. On the ride home, even a minor hill forced a downshift. I've never had the coach do that before.
My first thought was that I'd picked up a load of bad fuel with water or contaminates. Oh well, time to change fuel filters. On my coach the primary fuel filter (at least, this is what I understand is the primary fuel filter) is located on the passenger side in the small door that allows access to the chassis batteries. The filter is a Fleetguard FS19592. Now, here is where my ignorance shows through. Attached to the bottom of the filter is some kind of housing with a couple of electric wires and some 1/4" tubing. I must assume this is part of the air and water purge system, activated by the buttons in the engine compartment.
Now, how do I remove this housing from the filter? I don't want to start disconnecting stuff without knowing what I'm doing. I did try a search first, but couldn't find anything. Also, I'm having a hard time believing that a fuel filter would cause the symptoms I experienced, but because if happened immediately after refueling that's my first thought.
Glen
Glen,
The wires are probably connected to a water-in-fuel sensor. I use a rubber strap wrench to remove the filter after disconnecting the wires.
It looks like ours but yours has the water sensor. Disconnect the wires. Put gloves on and turn the plastic end CCW looking up at it from the bottom. Get a one gallon freezer bag to use so diesel does not go everywhere. The plastic bottom and the metal filter come off. Take a look at the new one and you will see how it goes on/off. You may want to look at the big O ring sealing the plastic bottom to the metal filter. Not a bad idea to also buy another plastic bottom.
With water in the primary, some may be also at the bottom of the secondary so change it too. After getting water, have at least two of each for spares.
If you have been running your generator at all since striking water, change it's filter too.
I prime ours but don't know your setup. Some engines don't take kindly to self priming the filters so check your procedure in manual or with another like owner.
Pierce
Don't prefill the filters. After they are installed use the Wynn priming system located near the remote engine starting panel at the rear of the motorhome.
Well, I changed the fuel filter after finding out that the water sensor thingamig was a separate part of the filter. It was pretty easy by using a plastic bag and a strap wrench. I didn't fill the filter with diesel, but instead when I got it back on I let the automatic air purge do its' thing, and the coach fired right up. I took it for a spin, and sure enough I think the problem is solved. Thanks for the help, fellas.
I'll have to order some spare filters. The local NAPA had only one filter at $39. I'd like to carry several in case I plug one on the road, but I think I can beat the $39 price.
How does the water sensor and drain work?
Thanks,
Glen
Glen,
Did you change only the primary? If so you may need to change the secondary (fine filter) now that you have taken it for a spin.
Pamela & Mike
The water sensor uses the conductivity of any water to turn on a dash light. Open the drain on the bottom of the bowl to release water. I've never seen any on mine.
Glen,
Water and algae are best buddies. If you still have the old filter, use a hacksaw to cut it open and check for black algae. The sensor may do a good job but visually check the clear plastic bottom for water every so often. Warm summer temps speed up the growth.
Pierce