Engine/Transmission (1994 - 1998) Fuel Filter.....Bad drip from valve

[TFPace]

I have a leak coming from my fuel filter water drain valve.



1. I have replaced the valve and it is still leaking.



2. Where is the "pressure coming from?



3. Precision said the the overflow valve will not cause the buildup w. i the filter.



4. Is this lift pump an issue?



5. Fuel hoses are new.



215,000 miles in this truck!



Thanks,



TP

 

[Dual EE]

I had a fuel filter leak from a seam before. It was leaking right where the drain valve screws into the filter. I put in a new filter and all was well.

 

[HEMI®Dart]

Did you use a new O-ring & dip it in lube and tighten it up nice?



If yes, I am stumped.

 

[biggy238]

the fuel filter is between the lift pump and the overflow valve. If the OFV is stuck shut it will overpressurize the filter.



You losen the bolt on the line from the t-pump in order to prime the line between it and the new filter, the other line runs to the injection pump and then through the overflow valve.



It does sound like a problem with the seal.

 

[Willys]

I've had a leak from the seam connecting the lower mounting area to the main filter body. If you look at the filter, the water sensor screws into the lower part of the filter, its a cylinder about 2" diameter(plus or minus an inch ), that is connected to the upper part of the filter(4" diameter?). The seam connecting these has leaked on mine before, it was a bear to diagnose, but when I took it off, there was a fuel stain coming from this area.



If this isn't it, the return and supply lines are just behind the filter, maybe they're leaking and spraying?



Edit: just saw that you have new hoses, probably the seam then... a new filter will fix that. Oo.

 

[TFPace]

Thanks for the replys!



I put a new WIX filter too.



The O-ring was lubed up.



The leak is definitely coming from the outlet in the valve.



I am guessing the OFV is bad or failing.



Remember the leak started with the original valve with 215,000 miles. I replaced the valve with a new one and it is still leaking.



I wish I could hook a tube to catch the drip. Parked it will quickly darken the pavement.



I have seen a post about the filter bursting due to overpressure. I would think this is due to the supply pump.



What route does the OFV return line take??? I would think it return line goes back to the tank? It is sounding like it goes back to the filter?



Keep up the good work!



TP

 

[Joe G.]

Do you have a fuel pressure gauge?



The input to the fuel filter banjo fitting may be leaking. The return line from the overflow valve goes to the return hose and then to the tank. The return line from the injectors returns to the fuel filter. It is the little pipe that goes from each injector and then goes between a couple of valve covers to the input banjo fitting to the fuel filter. That fitting is actually two banjo fittings stacked. At least it's that way on my '95. You don't say what year your truck is.

 

[biggy238]

On my last filter change I managed to pinch the return line (the soft part) between the fuel filter and the hard supply line that runs into the top of the lift pump.



If you replaced the return hose:



The return line runs rearward from the injection pump to right before the fuel filter housing. There, it turns into a soft line and then back into hard line that runs into a braided line that connects to the hard lines on the frame. If that soft line gets caught behind the fuel filter as mine did, you will have extremely high pressure.



Both the fuel and return lines run side by side to and from the tank. The return fuel returns compeltely to the tank with no other recirculation.

 

[TFPace]

Here's another question..... what is causing the over-pressurization of the filter?



Joe, my truck is a '94. Do you plumb in the gage before or after the filter?

 

[Joe G.]

After the filter. That way you can tell if the filter plugs up. The OF valve is the pressure regulator. If it is stuck closed or if the return line is blocked you will have excess fuel pressure. You need to have a pressure gauge to find out if excess pressure is what is causeing your problem. It is probably just an ordinary leak that is hard to find.

 

[Champane Flight]

Cracked

I thought my leak at first was the old return line failure. Then went and bought a new drain, turns out the filter was cracked from the drain valve across the bottom. By the time I zeroed in on it, I lost a few gallons (oiled my trailer) in around sixty miles of driving.

 

[vssman]

I had the same problem last summer that also ended up being a cracked filter right where the boss is welded to the outer case.

 

[BigPapa]

What kind of filters are you guys running that are cracked so much?



If the overflow valve has never been replaced then I doubt it could be stuck CLOSED unless he's stretched his spring too far and I still don't think it would stick closed.



TF, did you say it was leaking when the truck is not running? If that's the case there is no pressure and it's just dripping from either a bad valve, bad o-ring, or a bad filter. Within a 3 week period at around 180K miles I had the drain valve go bad, the return hose start leaking, and then the NEW drain valve go bad, so anything is possible.



Scott

 

[Willys]

Fleetguard, BigPapa, that's the only thing I've used for fuel filters since a NAPA one somewhere around 130k miles ago... I have replaced the drain tube because the insulation had pulled back off the wires near the connection to the sensor- so I'd get unreliable readings if it was wet.



Another thing I do now is to check that the filter stud(mounted on the engine, that the filter attaches to) is tight. If it's loose, it can be a bear getting the filter off. I had one I had to cut the filter off the mount(after the mounted was removed from the truck) with the sawzall. :--)

 

[vssman]

Mine was a fleetguard too...

 

[TFPace]

I know this sounds odd but is there a Fleetguard filter that uses a steel petcock inplace of the push in type of drain currently used on our trucks?



I have never had the water lite come on in 10 years.



Also, to install a fuel pressure gage, do you tee in between the filter and injector pump? What is the correct operating pressure.



Thanks,



Tom

 

[Joe G.]

I installed my fuel pressure gauge by tapping the banjo fitting on the side of the injection pump to 1/8" NPT. Then I used a needle valve to damp the pressure spikes and a grease gun hose to the pressure sensor. You should have at least 18PSI at idle and at least 21 or so at 2000 RPM with no load. Going down the road should show fuel pressures anywhere between 22 and 40 PSI depending on your overflow valve.



#ad

 

[Willys]

It occured to me today that dodge used a different style filter in the 94 to 96? model trucks than the ?97? to ?99?. I'm not sure how the drain is on the newer ones, hope my posting didn't confuse anyone as I don't know what year of the original truck is.

 

[TFPace]

Willys,



I would like to see the drain used on the newer filters.



I am at the point of trying to find a filter that has the metal petcock valve.



My leak is as strong as ever.



Where the excess pressure is coming from has me puzzled



Somewhere a fellow mentioned that the filter can would burst?



Best,



Tom

 

[Willys]

IIRC, the newer ones have an element inside a canister, I'm not sure how the drain works. My dad has a 98 12V, and he took the old filter out and installed the Prime-Loc kit, which uses the older filter. My mom still has the original, but there's a prime-loc in a box waiting to get installed. I'll see if I can find his old filter canister if I make it to his house in the next few days, and take some pictures for you.



Is it spraying fuel when the engine is running? Have you managed to get a pressure gauge installed yet?