Fuel union leaking

[Murv]

Best way to stop it?
The fitting seems fairly tight, but with 4 nuts, how do you actually tighten the fitting down?
Is it with a spanner on the two nuts at the extreme opposites, or does each side need tightening against the bracket?
I've tried nipping it up, too much force on the outer nut just spins the fitting within the bracket, a spanner on each opposite side nut stops it turning and it's tight there, but do I need to get a spanner on both nuts that are the same side of the bracket?
Obviously, it's virtually impossible to get to, and can only be reached with long spanners by laying on top of the engines and arms at full reach so replacing it is not an easy option.
To give a bit of scale, the nuts are 21mm so it's a fairly hefty fitting, can I tighten it down really hard or is that likely to strip the threads?
Hopefully the pictures will explain all:

Engine is a 1989 Volvo TAMD61A and the leak is on the all copper side

 

[volvopaul]

The copper pike side will have an olive at the end of the pipe that's squashed into the union which is a bulkhead fitting, renew the olive or try thread tape over it first , can be tricky if tank is full, is it on flow or return pipe?

 

[Murv]

Cheers Paul, I did wonder if PTFE might do it.
I don't know which pipe it's on, it's the bottom one that's leaking

 

[Freebee]

you need two spanners....... the nut next to the angle iron needs to be held steady by one spanner whilst you tighten (rotate) the brass nut that is right next to it which should tighten against an olive that is inside the fitting. the joint should need nothing else but tightening ......but if there is wear you may bodge it with ptfe tape which should be wound over the olive, but to make a proper joint you should fit a new olive... PTFE tape is never used for permanent pipe joins.

 

[Murv]

Thanks freebee, I'll give that a try.
The big problem is access. Had it been the other engine, there's room to st down there, stretch out and sup on a cuppa whilst doing it.
This one will probably see me hanging onto the window with my toes trying to wedge myself down the impossibly tight gap just to get a glimpse of it.
I'll try scrunching the thing up really tight, and if it gives, then nothing really lost anyway.

 

[ARE]

Locite 577.

 

[Boat2016]

Renew the olive is the correct way, PTFE is not to be used anywhere near diesel and will not fix the leak

 

[Keith-i]

As far as I can see, the thin nut shown in your photos against the angle bracket is just a locknut to hold the fitting in place. There should be nut on the other side which is the one you want to hold and then you can tighten the compression nuts on either side.

 

[rosssavage]

And don't forget - tighten the olive too much and it'll deform, and then cut through the copper pipe. Might fix initially, but a bit of vibration will soon chop through.

Replacing the olive is the only real fix, sorry!!

 

[Boat2016]

And looking at those pictures again it looks like the olives have been crushed as far as they can go, doesn't look like there's any more room to tighten, also check if correct olives have been used for the type of fittings

 

[oldgit]

Chris, without being funny..can you cut a discreet little hole somewhere opposite the problem then make up a neat little hatch or cover to make it look sort of original.
A-La-the Turbo 36 stern tube shower bodge,sorry modification.

 

[Hadenough]

As usual lots of contrary advice. You probably need to replace the olive but what they don't tell you is that will involve dissembling the joint, cutting the pipe and then fitting the new olive. First port of call is to crank up the nuts. If that doesn't cure it, bite the bullit.
.

 

[Murv]

Thanks all, appreciated.
It is the opposing locknut that holds it still, I'm going to take the floor up today to try and get a bit closer to it.
I might see if I can find the other end of it and see if I can get the whole section of pipe out to make it easier to work on.
Sadly, no possibility of an access hatch, this one is sandwiched between engine and fuel tank!

 

[oldgit]

Sadly, no possibility of an access hatch, this one is sandwiched between engine and fuel tank!

Ever felt an overwhelming urge to track down the designer of this boat and have a full and frank exchange of views about his parentage. !

 

[Murv]

Ever felt an overwhelming urge to track down the designer of this boat and have a full and frank exchange of views about his parentage. !

Now and again...

But, would also have to congratulate him on designing such a fine vessel at the same time!
This one just seems cruel though, there's absolutely no reason to mount a fuel union just out of reach when it could have gone absolutely anywhere. Ho hum!

 

[superheat6k]

So some "Not's" and "Never's" in the replies. IMHO it is the choice of the method is for the individual. Any one that works is the correct one.

I use one wrap PTFE with a smear of Loctite 577 on all my pipe joints and I do not have any leaks. The PTFE provides a small amount of flexibility in the joint. I am careful with both substances not to place either into the open pipe as these can cause issues with blockages down the line, especially if too much is used.

The issue Murv has is one of difficult access. If me I would open the joints by backing off the outer nuts which are holing the joints together, but this might require some fuel draining, wipe everything clean and dry, then use the thicker one wrap PTFE tape, with a decent smear of 577, then nip back up gently, refill, bleed the system out and check for leaks.

Another slightly thicker sealant to consider where access is at arms length is Gastite, normally used for calor gas fittings, as this has more body to it.

 

[Murv]

Thanks Trevor, it seems to be holding now

I found that by taking the (entirely reasonable) steps of: removing the furniture, carpet, floors and then floor bearers, it gives enough access to get two spanners on the thing with only minimal amounts of pain and without arms at full stretch.
Doing this allowed me to snug the joint up an 1/8th of a turn and it's been drip free since.
I'm still not convinced the tank isn't leaking, but I've now cleaned and dried the area under the union as well as the bilges and the section behind a stringer where fuel was accumulating and will keep a close eye on it.
If the union does weep again, I'll strip it down and reassemble as suggested.

 

[oldgit]

Fingers crossed Murv, It has obviously got worse as the boat has been used.probably vibration and the fact the boat had been idle for so long.,the problem was defintely not evident when she came back.

Its totally your fault of course all you had to do was to leave the boat tied up and not use it. !

 

[Murv]

Fingers crossed Murv, It has obviously got worse as the boat has been used.probably vibration and the fact the boat had been idle for so long.,the problem was defintely not evident when she came back.

Its totally your fault of course all you had to do was to leave the boat tied up and not use it. !

Nope, not my fault, completely the boats fault for being so ridiculously reliable!

I almost miss the good old days, filled with excitement and nervous anticipation at wondering whether the drive would hold together long enough to actually leave the pontoon or (invariably) not
I still can't quite get used to the fact that we now wander down and just... go boating

Just checked the log actually, 170.3 hours we've clocked now since purchase without a single breakdown!

 

[oldgit]

Nope, not my fault, completely the boats fault for being so ridiculously reliable!

I almost miss the good old days, filled with excitement and nervous anticipation at wondering whether the drive would hold together long enough to actually leave the pontoon or (invariably) not
I still can't quite get used to the fact that we now wander down and just... go boating

Just checked the log actually, 170.3 hours we've clocked now since purchase without a single breakdown!

Yea but do you not miss the "Good Old Days" of trudging into the clubhouse after watching all the the rest of the shaft drive boats disappearing into the distance on a glittering sun drenched sea for a cracking fun filled weekend somewhere ,while you ponder whats wrong this time with your outdrives, how much its going to cost and can you summon up the enthusiasm to jump into the car yet again to drive down and see us...
Happy Days.