Main fuel feed line leaking

[Dan O.]

Hi all,

one of the E420s in my project car fleet started leaking fuel, poor thing has been sitting for a LONG time so I'm not surprised. Borrowing a pic from another thread:



....the fitting at the tank, circled in blue - what is the preferred tool for dealing with this? I pulled the other end off the pump in order to drain what was left in the tank, one day though I'll have to change that hose and access seems pretty tight with the diff in place; at least I don't have to worry about that leveling valve.

 

[Kridre]

This is the tool that worked for me, along with the long extension, there is not much room to use anything else. You are probably going to unscrew this hose along with the fuel filter that lives inside the tank. I recommend you to replace it or at least clean it.

 

[nocfn]

If you are certain the hose needs to be changed out (and I would if its OE), then take it off of the filter end first. It will be easier to turn with a crows foot than a line wrench unless you have an offset one for the application (geek if you got one lol) As you suspect thngs can go bad so keep it ventilated, ground yourself to some bare metal, static electricity in the winter can carbq you quick.

 

[Dan O.]

Ok, great, I thought a crow's foot would be the answer. I had some concerns over whether or not a 'normal' -sized crow's foot would work, thinking about getting something a bit more close-coupled like one of the following:

01200008

<ul> <li>Chrome-alloy steel, chrome plated</li> <li>Please note: Changed setting values on the torque wrench</li></ul>

stahlwille.com

02190022

<ul><li>Chrome-alloy steel, chrome plated</li><li>Please note: Changed setting values on the torque wrench</li></ul>

stahlwille.com

22 mm Flare Nut Crowfoot Wrench | TEKTON | Made in USA

3/8 inch drive x 22 mm 6-point flare nut crowfoot wrench. Use to disconnect brake, fuel, and hydraulic lines without rounding-off fasteners. WCF16222

www.tekton.com

Regarding the strainer, I didn't really give it a good look last time I was there but once you get the fuel hose and rubber boot out of the way is it possible to unscrew the strainer from below w/o removing the tank? I know the strainer 'nut' dimension on a 300e is close to 41mm and oddly closer to 1 3/4", same for the V8 cars? Maybe I can get a socket of some kind in there?

 

[Dan O.]

This is the tool that worked for me, along with the long extension, there is not much room to use anything else. You are probably going to unscrew this hose along with the fuel filter that lives inside the tank. I recommend you to replace it or at least clean it.

View attachment 182295

In response to this, so glad to hear I'm not the only one and that step one in the factory-approved method ISN'T "drop differential"!

 

[gsxr]

You can R&R the feed hose with the differential installed, but believe me, if you do this... by the time you are done, you may wish you had just dropped the differential. Space is SO tight above the diff [Edit - this applies to the 036 and 034 with SLS, see post #13 below].

The crow's foot may not work well with the diff in place. If you don't drop the diff, access that fuel hose collar/nut with a standard open-end wrench slid below the fuel tank, from inside the trunk.

 

[Dan O.]

You can R&R the feed hose with the differential installed, but believe me, if you do this... by the time you are done, you may wish you had just dropped the differential. Space is SO tight above the diff. The crow's foot may not work well with the diff in place. If you don't drop the diff, access that fuel hose collar/nut with a standard open-end wrench slid below the fuel tank, from inside the trunk.

Oh no. Well I'm going to order a crow's foot and follow up w/my results once I have it. I thought about sliding a wrench under the tank from inside the trunk and gave this a half-hearted try last time I was in a wrecking yard, didn't seem possible given the wrench I had and how tight fitting the tank is. I must admit I was preoccupied by the idea of actually seeing what I was doing, the mechanics of making that happen with eyes located in ones head and the fitting where it is don't jibe. The idea is attractive though, possibly doable with a super thin wrench or some custom job I can fab up and camera assistance? I also learned that my local yard seems to take great pleasure in punching large holes in what were otherwise perfectly fine fuel tanks. I spent the remainder of my visit checking things out under different models, learned a lot about the subtle changes in fittings, early vs late strainers, etc. BTW, anybody ever looked at how the tank is shoe-horned between the top well and trunk floor on an R129? SO glad I'm not dealing with that, seems like it would be nearly impossible to get that tank out in one piece.

 

[gsxr]

I also learned that my local yard seems to take great pleasure in punching large holes in what were otherwise perfectly fine fuel tanks.

Yeah, Pick+Pull brand yards in CA and other states purposely destroy fuel tanks. I don't know why. Every vehicle in the yard has multiple large holes. Most other salvage yards don't do this.

 

[sheward]

I watched a yard monkey do just this. He rolled the car over with his fork lift and then punched a hole with the lift fork all the while grinning and explaining the easy way to drain fuel from the tanks before they go for scrap.

 

[Quick4door]

I finished replacing both the feed and pressure hoses when mine also sprung a leak this last fall. Honestly, it took maybe 45 mins start to finish, and dropping the subframe would only be a last resort for me. Both hoses from the classics center were around $200- not bad.

 

[gsxr]

I finished replacing both the feed and pressure hoses when mine also sprung a leak this last fall. Honestly, it took maybe 45 mins start to finish, and dropping the subframe would only be a last resort for me.

Did you do this on a 500E? If not, was it a 400E with ASR?

 

[Quick4door]

Did you do this on a 500E? If not, was it a 400E with ASR?

Admittedly this was on a 400e without asr.

 

[gsxr]

Admittedly this was on a 400e without asr.

I figured out the difference yesterday while working on my 034. Replacing the hose from the tank to the fuel pump is 1000X easier on the .034 chassis without SLS. There is pretty decent access to the bottom of the tank with or without ASR.

On the 036 (or, the rare 034 with special-order SLS)... it's the SLS bracket and valve that almost completely blocks access to the hose. Trying to replace this hose without dropping the diff or subframe would be a RPITA with SLS.

Photos below show the stuff in the way... the differential is removed here. The valve & hydraulic lines block almost all access from the driver side, and there's not better access from the passenger side either.

 

[Ian White]

$343 for clamps, tank to pump hose, line between pumps, high pressure line, purge value, vent hoses (except the 90 degree NLA hose), copper washers, rubber pump assembly mounts etc. $$$ Is it possible to purchase new fuel pump electric lug rubber insulator boots? Mine are rotten.

 

[dreaming.haze]

@Ian White - Takes a healthy amount of money to get the fuel system all the way squared. Currently in process of replacing all that you've listed with fresh rubber / hose / parts / etc.

To your question, I ordered the rubber insulator boots the other day on amazon: Amazon.com / Not OE, but they look to be the same general part and the "risk" for this insulator isn't high. If you want OE, pn: 123-997-16-81

For the NLA 90 degree hose, 124-471-32-23, I am testing out what hose will work for this. I've been able to cut up 208-476-17-26 to fit the same space of the 90 degree hose that was on my 400E. You can either buy OE... OR chance the CRP hose on FCP Euro or elsewhere.



Note, my 90 degree hose didn't look too terrible. It is the one on the right in the above image.

 

[Ian White]

That looks pretty great to me. Next will be fuel lines under the hood, we have a local shop (Spokane House of Hose, yes really) that makes custom hoses. We'll see how $$$ that will be.