Repairing a Banjo Bolt

JHZR2

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The fuel tank filler in my 93 300SD has a lot of rust. Probably because the car sat a number of years.

I want to put a Racor filter on it to help with keeping the IP safe, but I need to know actual flow rate. I tried to pull the return hose to measure the flow I get at idle and 2000 RPM. The hose would not come off. I pulled hard and broke the banjo.

F67CDDB9-8A9E-4DE4-8C7F-A4E763930AAD.webp


It just pulled out and I can’t get it back in. Not sure if it was soldered or what.

The hard line will spin inside the bore of the rubber hose, but it will not pull out. It’s stuck hard in the rubber return hose. The return hose is called a cigar hose, it’s bigger in the center than on the two ends. I’d like to avoid damaging it….

So any thoughts on how to fix the banjo bolt, and how to get the short part of it out of the hose without damaging the hose?

I’d like to take the car on a 300 mile trip early next week and obviously that can’t happen as is.

Thanks!
 
Buy a new one. Amazon has them. Mercedes parts suppliers (like FCP Euro) have them. Some options with overnight shipping. They’re pretty standard, based on the size of the banjo bolt and the outlet hose barb.
 
It might be a press fit. Worth a try. If not a quick braze job will do the trick.
 
Try heating the hose with a hot air source or two. And then try removing the part from the hose while it is still hot. I would use a hair dryer set on high, and maybe even an electric space heater at the same time.

Wear some kind of glove to protect you from the hot hose and hot metal. Twst and pull back and forth while pulling while everything is hot.
 
Buy a new one. Amazon has them. Mercedes parts suppliers (like FCP Euro) have them. Some options with overnight shipping. They’re pretty standard, based on the size of the banjo bolt and the outlet hose barb.
I should have been more clear. This is a hose that has three barbs, one tiny friction fit barb for the injector return, one 7mm that connects to the tank return and is held with a hose clamp. One connected to a hard plastic line that then has a another banjo bolt on it. More like an assembly, and the EPC says NLA.
 
It might be a press fit. Worth a try. If not a quick braze job will do the trick.
Does the ring of copper on this piece give a hint that it was brazed? I don’t have the tools to do so, thus I’ll have to remove the whole assembly anyway. Another thing that I just don’t have time to do. Ugh.

I’m going to try to put a 1/4 bolt through the broken nipple and tap it in. Maybe I should freeze the nipple and use a heat gun on the receiving side??
 
Cigar hose for diesel Mercedes is a common part. Check the length, maybe you can use one from an OM 616?

Then get two banjo fittings (one with a single hose barb, and one with two, to cover the various sizes) and stack them.

Get a long enough bolt and fresh sealing rings.
 
What does Benzworld say about this? I bet a search in the W140 section would turn up someone who has faced this before.
 
I should have been more clear. This is a hose that has three barbs, one tiny friction fit barb for the injector return, one 7mm that connects to the tank return and is held with a hose clamp. One connected to a hard plastic line that then has a another banjo bolt on it. More like an assembly, and the EPC says NLA.
One hose has three barbs?
 
I wouldn't do that, they are inserted in by machine and cannot be forced back in, it wont hold for long if at all. Maybe it is the pic but the end of that hose doesnt look that healthy either. Personally I would replace both.

I think it’s the original hose. It’s hard but didn’t leak or weep. Messing with it caused it to crack a bit. I will replace it. It was ok for what it was because it is a tank return line. Even if it caused some air entry it didn’t matter because it was going back to the tank. Air in the lines leading to the IP is obviously an issue.

The issue is that banjo bolt seems to be NLA and Pelican, FCP, etc don’t seem to have it. I’m not sure the MB Classic Center does either.

I will replace the rubber hose at this point.

Cigar hose for diesel Mercedes is a common part. Check the length, maybe you can use one from an OM 616?

Then get two banjo fittings (one with a single hose barb, and one with two, to cover the various sizes) and stack them.

Get a long enough bolt and fresh sealing rings.
No, the 603 has a much longer return hose. Mine kind of looks like a very long cigar hose, but other reports indicate that the 60x engines don’t use them. When I get the part number in the Mercedes EPC it’s just fuel line, not something special.
 
I thought the purpose of the cigar hose on the 616 (and 617) was damping pulsations from the the IP. But a long enough run of regular hose would serve the same purpose as a short run of fat hose.

I would replace that line.

Two banjos- two sizes of hose barb. New bolt. Stack them.
 
What does Benzworld say about this? I bet a search in the W140 section would turn up someone who has faced this before.
Peachparts (MercedesShop) has the stronger diesel community it seems and that one has slowed down substantially in recent years.
 
I thought the purpose of the cigar hose on the 616 (and 617) was damping pulsations from the the IP. But a long enough run of regular hose would serve the same purpose as a short run of fat hose.

I would replace that line.

It still looks to me like one barb on that center banjo. Why can’t that banjo be replaced?
That’s exactly it. The 603 can pump a lot more fuel from its lift pump than a 61x engine can, but I guess it’s sufficient.

The return hose looks “slightly”(?) cigar-ish?

0F6FC14F-EA9C-4627-B4C2-4039631245D7.webp

Just a much longer length. Maybe it’s just that old and failed. Don’t think so though… the original hoses on the fuel heater were solid and cracked but not swollen). The return line does see some pressure, maybe 12 or 18 psi IIRC.

Here’s the banjo:
956D02F5-76CD-462B-9E36-33752761E5D1.jpeg

Note the hard line that goes down behind the IP.

906B8D25-CB62-4064-96FD-484C2A710B8A.jpeg
 
Update, for the BITOG crew - two lines, including the hard line, are still attached. Hard line will break if removed.

So, keep the original banjo. Plug this line. Stack a new banjo with a barb for this hose. Replace hose. That’s my recommendation…
 
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