Fuel Filter

[Mickfly]

My fuel filter was dripping fuel so I changed the filter and put it all back together again and it is leaking again ( dripping ). Anyone else have this problem, am I doing something wrong? Thanks.

[Tillsy]

If from the top banjo did you replace the washer?

If from the bottom elbow fitting try some gas/fuel rated plumbing tape on the thread.

[Mickfly]

If from the top banjo did you replace the washer?

If from the bottom elbow fitting try some gas/fuel rated plumbing tape on the thread.


The washers that came with the fuel filter were larger than the one that were on there so I did not use them.

[DavidProehl]

Where is it leaking from? I know I had a horrible time with the tapered compression fitting (shown disconnected in the below picture in the middle of the filter).

31191

I had to crank it down almost to the point where I thought I would break something before it stopped leaking. It felt dangerously tight. Just be very careful you support that hardline. You have to do remove the body from the frame to replace that line should it break. Or you have to cut off the end and attach a rubber hose in its place.

[SS Spoiler]

I heard that some filters required double copper washers to get a good seal.

[PJ Grady Inc.]

Fuel filters with a cast steel top banjo only require a seal at the filter whereas with the brass banjo 2 seals are used (one at each end). You should always replace any fuel inj. copper seals IMHO although people often get away with reusing them. Remember fuel leaks are particularly dangerous on a Delorean.

The most common leak is at the bottom compression ring to the elbow fitting from overtightening the swivel nut. Once the compression ring is overtorqued you need to shorten the pipe by cutting off the ring and fitting a new one. This can be a prblem if the fuel pipe is distorted or rusted.

The crappy Chinese steel filters commonly sold now are about the same thickness as a beer can and distort easily. I much prefer the heavy aluminum older version which costs twice as much but is twice as strong.

One of these items is causing your problem. Please let me know how it turns out?

[Tillsy]

The washers that came with the fuel filter were larger than the one that were on there so I did not use them.

There's your problem then - no crush washer then no seal, no seal then fuel leak :)

[Nicholas R]

I heard that some filters required double copper washers to get a good seal.

I dot think 2 washers is ever really a good idea. It just creates another interfacing plane from which to leak. Also, copper washers work best when they seal against a material harder than the copper, because the copper deforms.

If you can't create a good seal, the sealing surfaces are likely gouged or pitted (washer faces included). Usually simply sanding the sealing faces with 120-220 grit sand paper will take away any of the pitting.

[DMCMW Dave]

I dot think 2 washers is ever really a good idea. It just creates another interfacing plane from which to leak. Also, copper washers work best when they seal against a material harder than the copper, because the copper deforms.

If you can't create a good seal, the sealing surfaces are likely gouged or pitted (washer faces included). Usually simply sanding the sealing faces with 120-220 grit sand paper will take away any of the pitting.

In this case the two washers go on either side of the banjo fitting, NOT stacked together on one side.

[Nicholas R]

Makes sense. For some reason I was thinking stacked washers, the way people will try to double head gasket warped or pitted cylinder heads. Never a good idea in my book.

[David T]

Makes sense. For some reason I was thinking stacked washers, the way people will try to double head gasket warped or pitted cylinder heads. Never a good idea in my book.

Doubling up cylinder head gaskets was done for another reason, to lower compression on older cars so you could run regular gas and save some money.

[Mickfly]

Ok, I found that it was leaking from the bottom part of the fuel filter. I tried using plumber's teflon tape on the threads but it still leaked. I ended up using pipe joint compound that has teflon in it and it worked!! Been driving the car now for three days and not one drop of fuel leaking. I'll keep you all posted if there is a change.

[PJ Grady Inc.]

Ok, I found that it was leaking from the bottom part of the fuel filter. I tried using plumber's teflon tape on the threads but it still leaked. I ended up using pipe joint compound that has teflon in it and it worked!! Been driving the car now for three days and not one drop of fuel leaking. I'll keep you all posted if there is a change.

A more secure fix would entail replacing the compression ring if the pipe is in good enough shape to allow it. Remember that the toasty catalytic converter is directly downwind from the filter but its your car and your risk. Keep an eye on it!

[DavidProehl]

Ok, I found that it was leaking from the bottom part of the fuel filter. I tried using plumber's teflon tape on the threads but it still leaked. I ended up using pipe joint compound that has teflon in it and it worked!! Been driving the car now for three days and not one drop of fuel leaking. I'll keep you all posted if there is a change.

The threads on the bottom joint aren't what is forming the seal (which is why that would have still leaked with teflon tape), it is the compression fitting. In my case, I had to crank on that compression fitting nearly to the limit of my strength before it would stop leaking. I tightened, checked for leaks, then tightened a little more, and repeated.

Like Grady said, your approach may only be a temporary solve. Watch it closely.

[Jimmyvonviggle]

Ok, I found that it was leaking from the bottom part of the fuel filter. I tried using plumber's teflon tape on the threads but it still leaked. I ended up using pipe joint compound that has teflon in it and it worked!! Been driving the car now for three days and not one drop of fuel leaking. I'll keep you all posted if there is a change.

Is pipe joint compound capable of withstanding contact with fuel? The reality is even though it is fixed now it is not a real solution. I don't think your safety is worth this Mickey Mouse repair, you should redo it or get someone to help you. Good luck.

[BABIS]

. I much prefer the heavy aluminum older version which costs twice as much but is twice as strong.



Where are these available?

[Bitsyncmaster]

The threads on the bottom joint aren't what is forming the seal (which is why that would have still leaked with teflon tape), it is the compression fitting. In my case, I had to crank on that compression fitting nearly to the limit of my strength before it would stop leaking. I tightened, checked for leaks, then tightened a little more, and repeated.

Like Grady said, your approach may only be a temporary solve. Watch it closely.

But the tape or compound would reduce friction and let you get more torque onto the compression fitting. I would just use some anti-seize on the treads.

[PJ Grady Inc.]

Where are these available?

We carry them if you don't mind the shameless plug. (100523G $24.75)

[PJ Grady Inc.]

Is pipe joint compound capable of withstanding contact with fuel? The reality is even though it is fixed now it is not a real solution. I don't think your safety is worth this Mickey Mouse repair, you should redo it or get someone to help you. Good luck.

If the line is in good shape you can just shorten it up to an inch or so (to avoid excessive rebending of the curves to re-align it) and slide on a new ring reusing the old nut. At about a buck it's a nobrainer!
If your pipe is totally rusted or distorted there is a slick new all stainless accumulator pipe with a built in braided section that allows a permanent replacement without pulling the body and would solve any and all problems. We have those too in case you ask!

[Chris 16409]

If the line is in good shape you can just shorten it up to an inch or so (to avoid excessive rebending of the curves to re-align it) and slide on a new ring reusing the old nut. At about a buck it's a nobrainer!

Rob, the fuel hoses that feed the pump use silimlar compression rings. Have you ever had to cut back the hard lines up there to install new rings. There isn't as much room up there so it would seem difficult.

[PJ Grady Inc.]

Rob, the fuel hoses that feed the pump use silimlar compression rings. Have you ever had to cut back the hard lines up there to install new rings. There isn't as much room up there so it would seem difficult.

Yes, but you can't use a tubing cutter there so it is more difficult but doable with some experience & finess.

[Mickfly]

We carry them if you don't mind the shameless plug. (100523G $24.75)

I could not find them on the web site, could you please post a link? Thank you.

[PJ Grady Inc.]

I could not find them on the web site, could you please post a link? Thank you.
My site is under new construction and I don't have much on it yet. Tons of parts sitting here waiting for new homes. Could you call it in? (800)359-7429
Rob Grady