Installing a new fuel filter

[sdg3205]

Perhaps my attention was too divided between the "FUEL" section of the manual and "The Sponge" episode of Seinfeld, but yeah, I couldn't find anything in the manual about the process for changing the fuel filter.

Is there anything I should know? How much gas will get in my eyes? Is pressure a problem?

Any advice would be greatly appreciated.

[Cory W]

If you have an oil catch pan, keep it under the car. And a roll of paper towels.

If the car's been run recently (anytime that would have rest pressure in the system), fire up the car and then trip the inertia switch (or pull the RPM relay, maybe Fuse 7) the car will die from fuel starvation. Pressure will then be minimal. If the car is cold and already elevated, you can just start.

The 90 degree connector at the bottom (intake) of the filter needs to be transferred over to the new filter. This seems to be the connection that leaks the most. Use teflon tape, but be careful none of it could break off and clog the line. Check wrench sizes, and always support the hard line if you're unscrewing that connector from the line.

The top banjo bolt should be 17mm. Do not reuse washers at this point. Go new or do it again.

The filter is held in place by a bracket that tightens around the filter with a screw, and is held to the frame by 4 bolts. I found it easier to make all connections, then put it back in place. Be sure the bracket is around the filter before making the connections. A foam like pad comes with it. Use it, but only put it in pace when getting ready to mount the bracket to the frame. You'll probably have to really open up the bracket to easily clear the padded section.

When it's all done, jumping the RPM relay builds the pressure back up in the system, and can show any leaks. Use a piece of clean paper towel to rub all around every connection you opened. If it comes back with any wetness, tighten that area just a little bit more. The filter is immediately to the left of the driver side exhaust system, so it's paramount you have NO leaks.

[jmpdmc]

Here is a pictorial of a fuel filter replacement: http://www.johnspangler.com/DMC/fuelfilter.html I have not used this as a reference but it seems logical.


Jeff

[Jonathan]

Make sure you support the metal fuel lines when you go to loosen those rusty 30 year old fittings. If you twist and torque the fittings and that twisting and torqueing travels down the direction of the accumulator, you can break a fuel line. To completely replace a fuel line, the body has to come up a bit off the frame as the lines are snaked in there between the body and frame. You don't want to have to do this.

[sdg3205]

Thanks everyone, this is exactly what I needed.

Sean - this information could be useful in the "How To" section.

[sdg3205]

That sucked!

But it's done and I have no leaks. I jumped the RPM relay and let it pressurize the system for at least a minute - a couple times. Checked with a new paper towel, no leaks.

The odd thing was upon removal of the old unit, I only had ONE copper washer - between the filter and the banjo bolt. The new one from DMC came with ONE washer as well, so for anyone doing this in the future, two are obviously not needed if your system doesn't leak and one is only found upon removal.

[outatym2001]

Dang Dave that was quick! You didn’t even give me time to post my comment regarding the fuel line on top of the fuel filter.
While you’re in there and replacing the fuel filter I would recommend replacing the plastic and rubber fuel hose that connects the top of Fuel Filter to the Fuel Distributor.
Maybe Toby at DMC Northwest has the stainless steel braided replacement. I know he has the six fuel injector SS braided replacements and I also know that DeLorean owners are too cheap to replace the 30 year old fuel hoses until they start leaking. *ducks*

Honestly I have not yet replaced the six fuel injector hoses yet with Toby’s replacement. I never seem to have the money when I need it. I did however replace the the fuel filter and the fuel hose between the filter and the distributor with a SS braided one from John Hervey. $57.50 part number 102365 for the SS braided fuel line.
http://specialtauto.com/delorean-parts/fuel-injection.html

[sdg3205]

Dang Dave that was quick! You didn’t even give me time to post my comment regarding the fuel line on top of the fuel filter.

Hahah! It didn't feel quick! Every time I think I've just completed one of the worst jobs on a DeLorean, a new and worse job crops up!

I hated changing that fuel filter. Dirt and gas was everywhere, which made me paranoid about fires. That thing is about an inch from the crossover pipe! WTF? no wonder the gas heats up!

Oh well, it's done now. Thanks for the tips on the fuel lines. They've actually been on my list for a long time. Since my car is mostly a garage queen these days (and since we're going into storage shortly) I don't see it happening anytime soon.

I'm heading down to see Toby today actually. Maybe I'l take a closer look at them.

[TripleZeroFilms]

That sucked!

But it's done and I have no leaks. I jumped the RPM relay and let it pressurize the system for at least a minute - a couple times. Checked with a new paper towel, no leaks.

The odd thing was upon removal of the old unit, I only had ONE copper washer - between the filter and the banjo bolt. The new one from DMC came with ONE washer as well, so for anyone doing this in the future, two are obviously not needed if your system doesn't leak and one is only found upon removal.

I actually just changed mine as well, only to find it had ONE washer as well. My Filter kit from DMC came with two (which I believe was a mistake, however, as the kit only listed one) but since the top of my banjo bolt is larger than the bottom, the washer(s) would only fit on the bottom. So while I just replaced the ONE washer I had with ONE of the new ones, I just wonder if this one washer setup is normal as most guides mention WASHERS plural.

I am now having a leak issue, so I'm wondering if this one washer setup might be the cause (but as I said I CAN'T use two due to how my banjo bolt is shaped). Any suggestions would be welcome!

[DMCMW Dave]

This is one of those things where there were variations in implementation at the factory. No rhyme or VIN-specific changes.

Sometimes you find the extra washer, sometimes not, sometimes the banjo bolt has the flat that seals against the brass banjo fitting, if so the washer won't fit there. If you have it back together and it's not leaking, consider it a success.

[Chris 16409]

Can anyone comment on the manufacturing change that Bosch made to their fuel filters that causes them to leak at the fittings. I heard this from someone, and that's why the filters had to be re-manufacured to original specifications.

[DMCMW Dave]

Can anyone comment on the manufacturing change that Bosch made to their fuel filters that causes them to leak at the fittings. I heard this from someone, and that's why the filters had to be re-manufacured to original specifications.

For a while the bottom (in DMC orientation) fitting was changed from a tapped hole to a floating nut. This would have been fine if the bottom fitting was a banjo bolt. Since it's not, screwing the elbow into a floating nut was a massive leak.

It was only at the one end, and I last saw this maybe 8-9 years ago.

[PJ Grady Inc.]

The cage nut design was used in an earlier Volvo application and for some reason Bosch switched from a pipe thread style to that design application over 10 years ago. I was not aware they ever switched back so I'll have to check with my Bosch WD to see what is currently offered (assuming they even stock it anymore).
I can provide more info for the two different (as in one versus two washer) banjo setups but I'll post it to the FAQ section (ASAP!) so that it'll be easier to find since this has come up before. So many questions keep coming up again and again that some of the answers would serve the group better filed in the FAQ section.
Rob


Can anyone comment on the manufacturing change that Bosch made to their fuel filters that causes them to leak at the fittings. I heard this from someone, and that's why the filters had to be re-manufacured to original specifications.

[Szabi]

Has anyone had fuel leak on top of the fuel filter? Today, after starting the engine, I found fuel under the car. I checked the fuel filter area with a small camera when the engine was on, but all I could see is that fuel was accumulating on top of the fuel filter pretty quickly. I cannot see where the leak is but the amount of spilled fuel is significant. That`s why I am not sure it`s just leaking at the copper washer.

I am also not sure if it has anything to do with this problem, but in the past few weeks the engine started with more and more smoke and more and more unstability at idling when the engine was cold. (After warming up, it was ok).

[kings1527]

Has anyone had fuel leak on top of the fuel filter? Today, after starting the engine, I found fuel under the car. I checked the fuel filter area with a small camera when the engine was on, but all I could see is that fuel was accumulating on top of the fuel filter pretty quickly. I cannot see where the leak is but the amount of spilled fuel is significant. That`s why I am not sure it`s just leaking at the copper washer.

I am also not sure if it has anything to do with this problem, but in the past few weeks the engine started with more and more smoke and more and more unstability at idling when the engine was cold. (After warming up, it was ok).

I've had that problem and it was as simple as the banjo not being tightened enough. That one can be a bit tough to get tight.

[Szabi]

I've had that problem and it was as simple as the banjo not being tightened enough. That one can be a bit tough to get tight.
Did you have the same symptoms before you found the leak (unstable idling, much smoke)?

[PJ Grady Inc.]

Since this problem appeared suddenly it may be a hose leak as opposed to a loose banjo or faulty copper seal. You should remove the filter (replace it if it's more than a couple years old) and thoroughly examine the hose for damage/kinking etc. If the hose is good check the banjo bolt for damage and replace one or both washers depending on the banjo style. A fuel leak in this area has a very high potential for fire due to the close proximity of the catylitic converter and crossover pipe. In short don't drive the car till you're positive the leak is fixed.
Rob


Has anyone had fuel leak on top of the fuel filter? Today, after starting the engine, I found fuel under the car. I checked the fuel filter area with a small camera when the engine was on, but all I could see is that fuel was accumulating on top of the fuel filter pretty quickly. I cannot see where the leak is but the amount of spilled fuel is significant. That`s why I am not sure it`s just leaking at the copper washer.

I am also not sure if it has anything to do with this problem, but in the past few weeks the engine started with more and more smoke and more and more unstability at idling when the engine was cold. (After warming up, it was ok).

[kings1527]

Did you have the same symptoms before you found the leak (unstable idling, much smoke)?

I never made it that far since I found the leak by jumping the RPM relay before starting it. Like Rob said, a leak in that area is bad, bad, BAD.

[Szabi]

Since this problem appeared suddenly it may be a hose leak as opposed to a loose banjo or faulty copper seal. You should remove the filter (replace it if it's more than a couple years old) and thoroughly examine the hose for damage/kinking etc. If the hose is good check the banjo bolt for damage and replace one or both washers depending on the banjo style. A fuel leak in this area has a very high potential for fire due to the close proximity of the catylitic converter and crossover pipe. In short don't drive the car till you're positive the leak is fixed.
Rob
Thanks, I`ll replace the hose and the banjo as both seems to be ancient.

[kings1527]

OK, so coincidentally I have to replace my fuel filter, too. I did it a couple years ago and the biggest problem at that time was dealing with the bottom conical connection and getting that connection to come apart. That was 2013. It's now 2015. Nothing has changed.

But this time is even tougher. I've removed the fuel feed line because I'm going to install a stainless braided line but I've managed to remove the feed line and filter. The thing that's still stuck together is the 90 degree elbow connection. I've twisted it, tapped on it with a hammer...nothing is getting that connection to budge. It's gotten looser and will twist a bit, but it's really stuck in there.

As an alternative, I can probably get another filter back in the car WITHOUT taking off the elbow but...any advice for getting one off that's REALLY stuck?


Next thing I'll try is using a torch. Just kidding.

[Jonathan]

OK, so coincidentally I have to replace my fuel filter, too.

Curious... what made you need to replace the fuel filter after only two years? Was it leaking? Or plugged maybe?

[kings1527]

Curious... what made you need to replace the fuel filter after only two years? Was it leaking? Or plugged maybe?

Performance has been fine but two years is the recommended service interval for the fuel filter. And there was definitely significant dark fuel coming out of it, so I'm happy I'm doing it. I'm not convinced fuel is as clean as we think it is. After I'm all done, I'll cut the filter in half and post pics so we can see what two years and about 9000 miles will do to it!

[PJ Grady Inc.]

Performance has been fine but two years is the recommended service interval for the fuel filter. And there was definitely significant dark fuel coming out of it, so I'm happy I'm doing it. I'm not convinced fuel is as clean as we think it is. After I'm all done, I'll cut the filter in half and post pics so we can see what two years and about 9000 miles will do to it!

If rapping the elbow sharply with a brass hammer (with the swivel nut backed off a few threads) doesn't work take off the 10mm brkt mtg bolts and try rocking the elbow back and forth with an open end 17mm wrench. Unfortunately the more you change the filter the harder the compression fitting seats into the elbow. Note-Never attempt to hit the line itself with a hammer or remove it directly with pliers etc.
Rob

[kings1527]

If rapping the elbow sharply with a brass hammer (with the swivel nut backed off a few threads) doesn't work take off the 10mm brkt mtg bolts and try rocking the elbow back and forth with an open end 17mm wrench. Unfortunately the more you change the filter the harder the compression fitting seats into the elbow. Note-Never attempt to hit the line itself with a hammer or remove it directly with pliers etc.
Rob

Thanks Rob. I tried that and even that didn't work for me. The only thing that was left on the hardline was the elbow and it wasn't coming off. So, I just left it on there and rotated the elbow towards me and screwed the new filter on that way. Then I put the top feed line on and rolled it all back into place. Caveman, but it all worked. And no leaks.

[SupercoolBill]

For a while the bottom (in DMC orientation) fitting was changed from a tapped hole to a floating nut. This would have been fine if the bottom fitting was a banjo bolt. Since it's not, screwing the elbow into a floating nut was a massive leak.

It was only at the one end, and I last saw this maybe 8-9 years ago.This literally just happened to me the other day. The wife and I were at the local auto parts and my wife asked if they had a fuel filter for a DeLorean. Akward........well guess what? They did! The guy says "Today's your lucky day"
"We ordered this in for a guy a long time ago and he never picked it up."
We went though all the aggravation of installing the fuel filter and it leaked like a sieve.

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