Good evening everyone,
What is the proper way to drain water from the fuel filters?
I think I have two in the engine compartment,
There is one at the back of the coach on the right side and another under the coach also on the right side.
I think there are also two filters for the generator accessible from the drivers side forward compartment.
Thanks
The filter in the front compartment is for the aqua hot and there should be a filter for the generator located to the rear and outside of the generator box.
Lt, Open the drain on the water separating fuel filter and catch the draing fuel in a clear container, clear glass or clear plastic cup. After draining 1/2 to 1 cup, stop the drain. Then examine the clear cup to see if there is a line between water on the bottom and fuel on top. If no line, test to see if all is fuel or water. If all fuel, you are good to go and all is well. If all water keep draing till fuel comes out.
Most of the time, you get fuel only.
When I flew Cessna planes, drained each fuel tank before each flight. Only once did I get water, it was all water, so no line. But did not look right. So drained a second time, got a line with water on bottom and fuel on top, Drained a third time, all fuel and a good flight. The planes had a special drain cup in each one.
Hope this helps
Yup, you are not draining a particular volume. If draining an ounce or two into a clear container shows only clear diesel, close it, you are done!
Both contaminants-- water and dirt are heavier than diesel and will be at the bottom of the filter where the drain is located.
You may have to let some air in somewhere to get anything to run out.
On my 1996 U320, the water/fuel separator is mounted on the frame behind the rear passenger tires. When the fuel level in the fuel tank is low (less than half), air will suck into the separator when the drain valve is opened. Air in the separator is not a good thing, so I often check for a line on the clear bowl attached to the bottom of the separator (indicating water) but will only attempt to drain water when the fuel tank is above 3/4 or when parked on a fairly steep uphill (puts fuel level above separator).
This is true of any of the fuel filters/ models. If the level of the fuel in the tank is below the level of the filter drain, it will "siphon" fuel back to the tank rather than draining out the filter. If above, fuel will run out the filter drain.
This is affected by: amount in the tank, installed level of the filter, as well as whether nose is higher or lower than the back.
so will air getting into the filter affect anything as stated above?
do I need to loosen the fuel cap to let air in?
It should not be necessary to loosen a fuel cap because the fuel tank is vented.
Fuel tank venting question. ??? (https://www.foreforums.com/index.php?topic=37035.msg354140#msg354140)
Letting air into the filter will create a stumble the next time the engine is started. Just don't drain too much, and be prepared to rev the engine on start-up until you clear the stumble.
If I suspect that there is air inside the fuel separator, I will suck it out rather than dealing with the engine stumbling.
I have a hand air pump hose (used to pump up bicycles tires) and attach the open end to a hand vacuum pump. Attach hose to schrader valve on top of the fuel separator housing and pump until diesel appears. I built this simple device when I replaced the OEM fuel/water separator.