Installing a new fuel filter

[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.