Fuel Filter Replacement Question

[Ron in SC]

This photo shows the fuel filter on my 99 ML 320. It the updated one. I need to change it. The connector with the bit of green on it needs to be removed as does one on the other end.

I really can not figure out how to get it off without breaking it. There must be a certain way to get this thing off; it must snap on the fuel filter outlet and inlet some way. But how?

[Ron in SC]

I found out their is a special tool called a 163 fuel line pliers sold by Assenmacher, part number 163 589 00 37 00 so I've just ordered one. While I have little doubt there are other ways or too to get those connectors off I'm not inclined to take a chance screwing something up.

[Gilly]

CANCEL the order Ron, this is the new stuff, you need the pliers for the old stuff.
On the one with the green on it, there is a small rectangular tab just above the green which can be pushed in by hand, and one I believe is 180 degrees opposed to that one, very easy.
The red one, MOST of the red mark is actually ON the part you press in on, although you wouldn't really need to disconnect it there if you don't want to (follow the line around to where it connects to the filter itself and disconnect it there).

Gilly

[Gilly]

Actually if you follow the plastic pipe around from the "red" connector it snaps onto the filter at the green connector.

Gilly

[Ron in SC]

Hi Gilly,

I just got back in town and read your posts.

Well that pliers is supposed to come today but I'm sure I can return it.

I did try to press on the little tabs by that green mark but I was unable to really push them in much; I know I don't have much hand or finger strength so maybe that's the problem.

Thanks,
Ron

[Ron in SC]

Gilly,

As you can see from the above photo I have very good access to the filter, but I just can not seem to get that connector off. I tried pushing connector but no success.

I can easily dissconnect the fitting by the red mark by pushing it in as you said.

Is there anything else I can try to get that connector by the green mark to dissconnect?

[Gilly]

You need to push at the top and bottom; there are 2 of the release tabs that you see at the top, one is clearly visible (the part with the 3 little ribs or slots) and one 90 degrees offset.


Gilly

[Ron in SC]

Gilly,

I really have tried to push those tabs in by hand and with that tool I ordered. I also did see the tab on the other side. I just can not seem to get them to go in far enough to release the connector from the nipple.

Is there maybe pressure in the tank that would prevent me from depressing the tabs and getting the connector off?

Or is this a situation of "Ron you need to push harder"?

I've put the liner and wheel back on so I'll try again another day. Hopefully I'll eventualy get that filter out.

I guess that not that many people have changed their own filters yet; as I can not believe I'm the only one having this much troulbe getting that filter out.

Ron

[Ron in SC]

Problem solved. Well maybe.

I went over to my dealer to have a look at the fuel lines and the connectors they sell when doing the filter upgrade. I could not depress the tabs on the connector even when the line was not fitted to a filter. The parts fellow checked with one of the technicians in the service department. He said all you do is depress the tabs with that Hazet fuel line connector tool. I certainly could not get them to move even with the fuel line connector pliers.

Well I messed around with the fuel line for a while and in doing so I think I figured out how those connectors work. I pushed both of those little tabs forward a little bit and I could easily depress both tabs. It appeared that the inside part of the connectors that must grip the nipple or whatever it’s called on the filter moved a little bit.

Maybe that’s how they work.

[Ron in SC]

I installed my new filter and vehicle runs fine. I did get a check engine light which must be related to the install. I'll have a friend read code and reset light tomorrow.

Installing this filter is a pain. While my experience working on a lot of different cars is limited I can not help but conclude that the design and engineering that led to the decision to place the filter in its current location is to put it simply, not good.

[Ron in SC]

The code, which I cleared, was P0304 cylinder 4 misfire dectected. I didn't hear any misfire. Maybe that's just the code it shows when you put in a new fuel filter.