Community Forums

Frank94062 · 07-22-2018, 03:43 PM

Hi,
I tried to replace the Alliance filter element in the fuel/water separator and ran into a problem. Hope someone can help me with this. Following the directions I opened the drain on the bottom of the canister bowl to drain the fuel. After draining a gallon of fuel, which is far more than the element holds, I stopped. It seems that the whole fuel system was draining out. What am I doing wrong?

RJ51 · 07-22-2018, 08:03 PM

There is a nut/vent on top of the filter bracket that you need to loosen. fuel won't continue to flow once the bowl and the filter drains.

Algoma · 07-23-2018, 06:13 AM

I had the same problem, so I called Freightliner. The filter is at a low point so you will lose fuel whatever you do. Freightliner uses a big bucket to catch the fuel and changes the filter as quick as they can while fuel is running out. They didn't see the need to move the filter to a better position or add a shutoff.
So my trick is: (1)only change the filter when you have less than 1/4 tank of fuel, (2) raise the rear of the coach so the filter is as high as possible.
I changed mine last week using this method and I was able to completely drain the filter and remove it without any fuel loss.

Frank94062 · 07-23-2018, 12:53 PM

I am parked on level ground and have almost a full tank. I opened the vent cap on the filter it didn't help, the fuel continued to flow out. This time I drained out almost two gallons before I stopped trying. Sounds like I need to try it on a slope with an almost empty tank or take it to Freightliner. Hard to believe Freightliner doesn't have a better solution.

RJ51 · 07-24-2018, 12:54 AM

I don't know what year coach you have but I just changed my filter 2 weeks ago and had no problem with fuel continuing to flow. In the picture you can see part of the bolt that is the vent (circled). And here is the instruction from Freightliners maintenace manual page 47.

47–02 Fuel/Water Separator Element Replacing

Alliance

The only maintenance necessary on an Alliance fuel/water separator is to replace the filter
element.

WARNING

Diesel fuel is flammable and can ignite if exposed to an open flame, intense heat, or other
ignition source. Do not drain fuel near, or expose fuel vapor to open flame or intense heat.
Exposure to open flame or intense heat could start a fire, pos- sibly resulting in personal injury
or property dam- age. When working on a fuel system, have a fire extinguisher within easy reach.
1. Drain off some fuel by loosening the vent plug and opening the drain valve. See Fig. 1.
2. Disconnect the water sensor and heater connec- tions if equipped.
3. Remove the element and bowl together, by turn- ing counterclockwise.
4. Remove the bowl from the element and clean the O-ring seating surface.
5. Apply a coating of clean fuel or motor oil to the new O-ring and element seal.
6. Spin the bowl onto the new element, then spin them both onto the filter head, snugly, by hand
only.

IMPORTANT: Do not use tools to tighten the bowl and element.

7. Connect the water sensor and heater connectors if equipped.
8. If equipped with a primer pump, prime the fuel/water separator.
8.1 Loosen the vent plug. Then operate the primer pump until the fuel purges at the vent plug.
8.2 Close the vent plug.
9. Start the engine and check for fuel leaks.
10. Shut down the engine and correct any fuel leaks.

RJ51 · 07-24-2018, 01:02 AM

Also from the manual.

Frank94062 · 07-24-2018, 07:07 AM

I have a 2017 Ventana 3436. I first loosened the vent and still got 2 gallons that drained out the bottom. I then removed the vent bolt and fuel gushed out the vent. I appreciate all the detailed help...something in my situation is causing this. An almost full tank of fuel and level ground?

RJ51 · 07-24-2018, 03:05 PM

Quote:

Originally Posted by Frank94062

I have a 2017 Ventana 3436. I first loosened the vent and still got 2 gallons that drained out the bottom. I then removed the vent bolt and fuel gushed out the vent. I appreciate all the detailed help...something in my situation is causing this. An almost full tank of fuel and level ground?

Very puzzling. I had a full tank of fuel and level ground also, but no continued flowing of fuel after I vented the filter.

The only suggestion I can offer is and maybe you tried this is to open the vent and drain the fuel out of the filter and then close the vent and see if it still fills the bowl.
Bad filter housing bracket?

C.Martin · 07-24-2018, 03:20 PM

It would be nice to have a couple of shut off valves near the filter. But...we don't so it's a diesel bath.

The way that I do it involves a few steps.

First...I have a plastic container that a filter element fits inside. The container is flat bottomed...so it holds the filter upright to prevent it from tipping over.

I prepare by using an extra sight bowl. I add a drop of oil to the rubber gaskets...and attach the sight bowl to the new filter. I sit it inside the flat bottomed container to hold it upright and fill with clean diesel fuel.

The next bit of prep involves me going underneath with some aluminum foil. I wrap all the exposed wires, hoses near the filter...so that they don't get soaked with diesel fuel during the filter swap.

I place a catch pan under the filter...and ready the new filter for a quick swapout.

Remove the old filter and let it rest in the catch pan...and quickly connect the new filter. Having some rags or paper towels at hand helps remove spills from your skin quickly after the operation. Remove the foil protection and you are done.

I usually crank the engine and let it run for a while to make sure the line is primed and not going to give me troubles the next time I go to start the coach.

Then remove the sight bowl from the old filter...wipe it down and store it for next years swap out.

Algoma · 07-24-2018, 03:29 PM

Quote:

Originally Posted by RJ51

Very puzzling. I had a full tank of fuel and level ground also, but no continued flowing of fuel after I vented the filter.

The only suggestion I can offer is and maybe you tried this is to open the vent and drain the fuel out of the filter and then close the vent and see if it still fills the bowl.
Bad filter housing bracket?

The problem is you have a Dutch Star and your filter is in a totally different place.

RJ51 · 07-24-2018, 04:31 PM

Quote:

Originally Posted by Algoma

The problem is you have a Dutch Star and your filter is in a totally different place.

Ok thought it was the same. Ventana's have the rear radiator, forgot about that

Frank94062 · 07-25-2018, 08:52 AM

Thanks for all feedback. I noticed the difference from the photo above. In the photo the fuel line runs from below the filter up alongside the filter. On my coach the fuel line comes straight in from above.

Caymanedge · 09-17-2021, 07:11 AM

Old thread but.....what is the procedure to prime the fuel/water separator after it's changed? TIA

Just George · 09-17-2021, 03:03 PM

The process described by C.Martin is the process I use. It's a bit messy but based on my discussion with Freightliner that the way it's done. Probably no need to but I turn the ignition on for 30 seconds and off ~ 3 times before attempting to start just to ensure the filter is full. When you prefill the filter fill clean diesel into the outer holes NOT IN THE CENTER.