Fuel Filter Nightmare...

[Koko4]

I decided to replace the fuel filter, following these simple instructions:

5VZ V6 4runner fuel filter write up with pics | IH8MUD Forum

Got the old one off, put the new one on, and started it - had a leak from the front of the filter. I put the old one back on, and tightened it to the same tightness... it calls for 18ft/lbs so I did it a bit past snug. Essentially until the threads hit. With the old one back on, there were no leaks. Took the replacement fuel filter back to Toyota and exchanged it for another one.

Now, after I install this second replacement filter, it leaks out of BOTH sides. I carefully took everything back off, and physically held the fuel lines against the filter while I tightened it back up...and it still leaks.

Am I doing something wrong? I don't want to overtighten this thing, but I'm guessing it might need a good bit of torque to get it to where it doesn't leak. The last thing I want to do is break the fitting on the fuel lines themselves. I'm just baffled that the old one would have NO leaks and the new one would leak like crazy!

Before I ask this, I'm already assuming that teflon tape is a big no-no? No type of o-ring or gasket came off of the old ones, so I'm assuming that's not the issue. Please help! I'm at my wit's end.

 

[Brian757]

It seems that the threads aren't catching properly. I replaced my fuel filter a couple weeks ago, and had some difficulty threading in both sides.

I bought a Purolator fuel filter from AdvanceAuto and it took all of about 20 minutes to replace. No issues other than threading in the new one, but it took about 2 minutes to get both sides settled and I threaded them manually. Once I got both sides on properly, I then wrenched it to 18 ft/lb.

Here is what I did: Go to www.advanceautoparts.com, and type in your Year, Make, and Model. After that, put a Purolator fuel filter in your cart, and a Purolator PCV valve in your cart. The fuel filter is $25 and the PCV valve is $5. Then use the Promo code, A124, at checkout. This gives $10 off of $30. So for $20, you will replace your FF and PCV valve. (ONLY USE THIS IF YOUR NEAR AN ADVANCE AND/OR YOU HAVEN'T REPLACED PCV YET.) Online ordering allows you to apply promo codes AND opt to pick it up at the store of your choice.

If all else fails, you can wraps the threads of the piping with plumbers's tape (thread seal tape, Teflon tape). Teflon tape is fine but keep an eye on the seal over time, if it doesn't leak at first. Fuel is corrosive and if the teflon is the only safeguard against the leak, the fuel will certainly makes its way through it.

 

[Brilliant]

Use a flare nut wrench? If not, that's your problem. I couldnt get it seated right with a std wrench.

 

[Koko4]

I was using a 14mm flare nut wrench on the line, and a 19mm wrench on the filter itself. I managed to get the back leak-free by tightening the $&$% out of it, BUT the front still drips. One drip starts accumulating at the threads, and it takes about 20 seconds for it to turn into one actual droplet. I don't know if I should unscrew the entire fuel filter again, and teflon tape the front fitting, or if I should just leave it like this. I was tightening it to hard that in the front, the FLARE nut wrench was starting to round on the flare nut. Craziness...

 

[Brian757]

I was using a 14mm flare nut wrench on the line, and a 19mm wrench on the filter itself. I managed to get the back leak-free by tightening the $&$% out of it, BUT the front still drips. One drip starts accumulating at the threads, and it takes about 20 seconds for it to turn into one actual droplet. I don't know if I should unscrew the entire fuel filter again, and teflon tape the front fitting, or if I should just leave it like this. I was tightening it to hard that in the front, the FLARE nut wrench was starting to round on the flare nut. Craziness...

I wouldn't leave it that way. You will lose a great deal of fuel over time.

 

[KidVermicious]

I was using a 14mm flare nut wrench on the line, and a 19mm wrench on the filter itself. I managed to get the back leak-free by tightening the $&$% out of it, BUT the front still drips. One drip starts accumulating at the threads, and it takes about 20 seconds for it to turn into one actual droplet. I don't know if I should unscrew the entire fuel filter again, and teflon tape the front fitting, or if I should just leave it like this. I was tightening it to hard that in the front, the FLARE nut wrench was starting to round on the flare nut. Craziness...

You are using fresh copper washers, right?

Don't leave it like that. A fuel leak is nothing to screw around with.

 

[Koko4]

You are using fresh copper washers, right?

Don't leave it like that. A fuel leak is nothing to screw around with.

Fresh copper washers? What do you mean...there were no washers / o-rings that came off the old one. It was just male-to-female compression fittings..

 

[KidVermicious]

I've never played with the 3rd gen fuel filter, but I'm assuming they're banjo fittings on the fuel lines? They need copper washers on both sides. There should have been fresh ones in the box with your new fuel filter, but if not, take the banjo bolts into the parts store and they should be able to hook you up. You need two for each side.

 

[Koko4]

I've never played with the 3rd gen fuel filter, but I'm assuming they're banjo fittings on the fuel lines? They need copper washers on both sides. There should have been fresh ones in the box with your new fuel filter, but if not, take the banjo bolts into the parts store and they should be able to hook you up. You need two for each side.

It just has compression-type fittings - it looks like this:

There's a tapered end on the fuel line itself, and then a opposite-facing tapered end on the fuel filter itself. I'm afraid I tightened it to WAY more than 19ft/lbs, however the more I tightened the less it leaked..

I think I'm at the point where it won't tighten anymore.

 

[KidVermicious]

Ignore me then, I don't believe you need copper washers for that style.

 

[Koko4]

Dang..I was hoping it would be an easy fix. This was supposed to be the EASIEST thing on my list of things today (fuel filter / antenna / rewire rear window switch) but it's turning out to be a literal nightmare. Is there any kind of sealant I can use? (I read that teflon is a big no-no)

 

[KidVermicious]

Permatex makes a thread sealant that is supposed to be fuel safe. I'm worried that's a bandaid, but I guess if the filter stays on and doesn't leak then it stays on and doesn't leak, right?

 

[amalik]

Having your old filter on there that doesn't leak might even be better than this situation.

Is the old one OEM as well? Same exact part as the new!?

 

[HiLife]

If worse come to worse, the price of a leaky fuel filter is not worth it compared to the price of repairing, or replacing your 4R.

Doesn't hurt to double check if copper washers or some other oem sealing methods should be used in your application.

If it was available I would have used a Toyota filter if I encountered problems using other aftermarket filters. You don't want to take a slight fuel leak lightly.

It's always better to be safe than sorry.

 

[SweetWaterSurprise]

At least you were able to get the old one off. Mine is beyond stuck even after soaking the nuts.

 

[HiLife]

Oops, my apologies, you are running a Toyota oem fuel filter.

 

[amalik]

the other option you have is this...

put the old one on... take it to a shop and pay them to put the new one on. you should be able to finalize a labor price before starting. once they run into leaks/crap with the new filter, it's not your 'DIY' headache anymore, and they probably have more experienced people who have run into similar stuff.

 

[Swimmerboy2112]

I replaced mine about a week ago. There are no o-rings or washers.

If I were you, I'd take a wire brush and gently clean the threads on the fuel lines. Perhaps some rust or debris got on the threads thus not allowing it to seal properly.

 

[Brian757]

the other option you have is this...

put the old one on... take it to a shop and pay them to put the new one on. you should be able to finalize a labor price before starting. once they run into leaks/crap with the new filter, it's not your 'DIY' headache anymore, and they probably have more experienced people who have run into similar stuff.

This is actually a pretty good idea if all else fails. Put it in someone else's lap. And they won't charge much to install a fuel filter. I would consider this option OP.

 

[Nelsonmd]

Maybe a dumb question, but when you had the filter off, did you inspect the faces of the pipe flare and the face of the compression fittings on the filter? If you have some scratches of damage to the flare end of the pipe, or to the brass compression cone inside the filter fittings, then that could be causing your leak path.

The threads aren't what seals a compression fitting, so if you are leaking, you need to look at the actual contact surfaces for the leak.