Crallscars

My water in fuel light keeps coming on, I would bleed the separator with good success. But most recently, I would bleed it with no success, I changed filter and bleed again and light is still on.

Could the sensor be bad? How do you test it?

oliver foster

When you bleed it does water come out?
I like to try to bleed it into a cup so I can see what comes out.
If the light keeps coming on, you might have a lot of water in your tank...

Crallscars

The problem is, the light stays on.

That's why I am curious if it is a bad sensor, or if the sensor needs to be cleaned.

oliver foster

It is just two prongs in there.
When the water gets high enough in the fuel filter it allows the two prongs to flow electricity and turns on the light.
The sensor just threads into the fuel filter, it would be easy to pull out check, clean or replace.
I have never seen one go bad, but I am sure it could.
I would just be worried about it being on because there IS water in the fuel.

oliver foster

I have had a bad tank of fuel and I had to drain water out of the filter several times over 30 miles, as it pulled in the water off the bottom of my tank.
When the light came on I just pulled over and drained it till it went off, then repeated as needed.

Crallscars

I had been clearing the light by draining the filter with good success. The last few times I have bleed the water separator, it didn't go out, I even tried changing the filter.

If I was getting more water in than I was bleeding, I would think it would show up in the performance of the engine, that's why I am wondering if it's the sensor.

oliver foster

If it was my truck I wouldn't wait till performance of the motor was effected.

I will ask again…Does water come out of it when you drain it?
If so keep draining it.

Busboy

I agree the last thing you want is water mixing with the sulfur in the fuel, I would also check the connector for the sensor, clean it and put some electrical grease silicon grease on the pins.

Crallscars

All good suggestions, tonight when I get home I am going to bleed the separator into a glass cup and see if there are any signs of water, then clean and grease the connectors, if all else fails, remove the sensor and clean or replace.

There are 2 things on the side of the separator, which is the WIF sensor?

oliver foster

The drain plug in the bottom of the fuel filter is the water in fuel sensor as well.
If you changed out the fuel filter already you have to un screw the sensor and re-use it with the new filter.
If you have another wire going to a disk that is above the filter, that is a pre heater, and should have nothing to do with your problem.

The sensor is fairly cheap, and easy to replace.

I would just be worried that the sensor IS working and you have a filter half full of water.

oliver foster

Actually depending on your year 2nd gen, you might have the later style black fuel filter housing.
IF so ignore my Sensor location info, as that is the '94-'97/'98 style fuel filter housing design.

Crallscars

I had a 1992 with the bottom sensor/drain, this truck, a 2001, has the later black filter assy. with the screw on lid.

If I remember Correctly, there is the drain valve with the lever, and I think 2 assy.'s with wiring harnesses attached, which is the WIF sensor? and what are is the other?

oliver foster

Funny thing is I just fired up my '95 at lunch, and the WIF light came on.
I drained the filter several times, bleed the air with the lift pump, and fired it back up, with no light on.

My '01 I swapped in an Air Dog with the filter and WIF filter in line and did away with the black filter unit.
The other '97 I had with the black canister I swapped out to the earlier spin on filter assembly.
So I am not sure of the WIF sensor on the later style.
You are correct with the tube to the yellow drain valve on the later style.

I am sure someone will chime in with better later filter housing info.

Crallscars

Mine is a late 01, the valve is a lift type lever, and there is nothing yellow.

Should I drain the filter/separator completely with the engine off?

I have been just draining a small amount, 1 or 2 seconds, while the engine is running.

oliver foster

I ended up trying to just drain it 1/2 to 3/4 of the way with the engine off, so I would not starve it of fuel.
After 3 attempts like that, I drained it 100%, then I had to use the lift pump to partially fill the filter back up again.
It ran rough for a moment, than smoothed out.
If that had not done the trick, I was ready to swap in a new filter [pre-filled] even though I swapped that one out in January.