Volvo MD22L-B fuel dripping from air intake

Feb 10, 2004
4,129
Hunter 40.5 Warwick, RI
UPDATE:
Being desperate for a way to stop the leak that I found at a return line connection to a Tee fitting, I wrapped the leaking joint with RubbaWeld tape.
2023_0929_101254.JPG

The RubbaWeld tape stopped the leak for a month or longer but I viewed it as just a 'bandaid' fix. So today at anchor in the rain I decided to attempt a better repair as @Ralph Johnstone outlined in post #46.
So I removed the RubbaWeld and of course the leak was still there. I loosened the compression nut and pulled it back on the tubing. What I found was that the compression ferrule was stuck inside the nut and it pulled back with the nut. There was no indentation in the tubing where the ferrule should have been pressed into it. I thought this was very strange.

Looking into the threaded end of the compression nut I observed that the ferrule did not appear to be brass or steel but looked like rubber or some kind of polymer material. Bottom line, I could not get the ferrule out of the packing nut, so doing a fix like @Ralph Johnstone suggested was not possible. Below is a picture I took with my boroscope looking into the packing nut.
20230929114147.jpg


I did some research on the 'net and found that there are non-metal ferrules and that they are used in high vibration applications. They seal the tubing without deforming it as a metal ferrule would do.

So I simply re-assembled the joint and tightened it quite tight. Running the engine for a short time to fill all of the tubing produced no leaks. Maybe just the disassembly and re-assemble has fixed the seal? I don't believe in magic.

So I am going to keep an eye on this joint and if I see any leakage, I will take another 1/8T on the packing nut. I may have to re-apply the RubbaWeld tape as a final fix.

So my question to all of you experts:
Have any of you actually seen rubber ferrules used in this (or any) application? Their existence is a new one for me.
 
Jan 4, 2006
7,247
Hunter 310 West Vancouver, B.C.
Have any of you actually seen rubber ferrules used in this (or any) application?
The only close application I've dealt with is nylon ferrules on vinyl tubing for pneumatic instrumentation.

I may have to re-apply the RubbaWeld tape as a final fix.
I still am fixated on any seal mechanism must be inside of the fitting and for that reason, I still think you're in perfect condition for a permanent fix. This is only sealing against atm. pressure. The big question is : can you slide the nut and plastic ferrule off the tube ?

If you're anywhere near civilization, check out a plumbing store for bathroom repair kits which have nylon or any polymer ferrules. I've seen them but can't remember what they're for. Maybe the mfg. had a reason for the polymer ferrule rather than a metal one. The plastic one will still do a perfect job on the low pressure application.

Maybe just the disassembly and re-assemble has fixed the seal?
If the ferrule hasn't deteriorated because of the fuel, that may well have happened. Use parting compound on the threads if they are getting tight for whatever reason.
 
Jan 4, 2006
7,247
Hunter 310 West Vancouver, B.C.
I guess you didn't bother to read post # 51.
Are you sure copper ferrules are used? I have worked on several diesels (John Deere & Cummins) that use a rubbber gasket instead.
Ah yes, who could forget post #51 ? Good Lord man, can't remember where I left my keys half the time let alone post #51. It's either the Cummins rubber gasket or a plastic one from a plumbing supplier :

1696046391051.png


They're soft, they're mushy, they just might work. Various sizes from Home Depot. Something's got to fit and hold 0 PSI.
 
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Feb 10, 2004
4,129
Hunter 40.5 Warwick, RI
I guess you didn't bother to read post # 51.
Oops, you are right. I did read the post but I had forgotten about it. When I read it, your word "gasket" threw me off because I was thinking "ferrule". But understanding that you meant a rubber ferrule, it all makes sense. So I have learned something- rubber ferrules are a 'thing". Thank you.

The only glimmer of hope is that after re-asssembly yesterday, there is no leaking from this joint. So maybe the seal quality is "repaired" with the R&R of the joint? One can only hope.
 
Jul 23, 2009
893
Beneteau 31 Oceanis Grand Lake, Oklahoma
You tried.
Yes, I went to bed immediately after posting that.

Edit I read that as "tired" instead of "tried". Sorry

I'll post a picture of the rubber ferrule if I can find it.
 
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Jul 23, 2009
893
Beneteau 31 Oceanis Grand Lake, Oklahoma
Ah yes, who could forget post #51 ? Good Lord man, can't remember where I left my keys half the time let alone post #51. It's either the Cummins rubber gasket or a plastic one from a plumbing supplier :

View attachment 220353

They're soft, they're mushy, they just might work. Various sizes from Home Depot. Something's got to fit and hold 0 PSI.
Ralph, that wasn't meant for you. Sorry about that.
 
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Jul 23, 2009
893
Beneteau 31 Oceanis Grand Lake, Oklahoma
I looked for a spare rubber ferrule in my work truck, but I couldn't find one. It really just looks like a very thick rubber washer or maybe a 3/16" section of 1/4'" fuel line. I bet a slice of fuel line would work in an emergency.
 
Jan 4, 2006
7,247
Hunter 310 West Vancouver, B.C.
I bet a slice of fuel line would work in an emergency.
Given the requirements, I'd say that's the easiest and 99.99% guaranteed given the ability to conform to the interior of the nut and exterior of the tube.

Ralph, that wasn't meant for you. Sorry about that.
Ah, what the hell. If the shoe fits ...................................... :laugh:
 
Feb 10, 2004
4,129
Hunter 40.5 Warwick, RI
Update after 5 days.
No more seepage or leaks. I've run the engine about 4 hours and checked each day for the fuel leak to return. It has not.

So maybe disassembly and re-assembly of the leaking joint has sealed it. I am home now and will check it again after 7 days. The leak was all the time, running or just sitting.

I should probably buy a rubber ferrule just in case it starts leaking again so I could change the ferrule out.

Thanks to all who contributed ideas to help me.

Now if I could just find the source of my small antifreeze leak I would be totally happy.
 

dmax

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Jul 29, 2018
1,193
Telstar 28 Buzzards Bay
and ball bearings:
Fletch : Awww, come on guys, it's so simple. Maybe you need a refresher course.


[leans arm on hot engine part]


Fletch : Hey! It's all ball bearings nowadays. Now you prepare that Fetzer valve with some 3-in-1 oil and some gauze pads. And I'm gonna need 'bout ten quarts of anti-freeze, preferably Prestone. No, no make that Quaker State.

 
Nov 21, 2007
673
Beneteau Oceanis 34 Kingston, WA
Sorry that I missed all of this fun, it sounds like my search for the source of water that I find after motoring for the last several years. Just when I think I've found it...I probably really don't have to finish that sentence. I hope to pick up a new seawater pump for my 3YM30, either today or tomorrow. Then I get to attempt to install it with my fingers crossed.

Back to this topic. I used to work with Aeroquip hose and fittings when I was doing my SCCA racing. Hoses, fittings, and adaptors available in many sizes, and it wasn't expensive at all. I haven't shopped for any of it in quite a while, but it should be available à la carte from any local performance shop, especially racing suppliers. You could build an entire replacement assembly and just swap it out for less than a single Volvo return pipe, and have plenty left over for a celebratory toast afterward.

Fuel line kit from Amazon

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