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Going on roughly 2 weeks of trying to get the coupling at rear of the fuel hard line off and have zero clue of what to do. Up to this point I have:
- Applied multiple rounds of PB Blaster, letting things sit over the evening.
- Applied multiple rounds of CRC Freeze-off, preceded by some heating of the line with a heat gun first, letting things sit for a while between treatments.
- Applied multiple rounds of some other rust-buster I had, letting things sit over the evening.
- Had it sitting in an ATF/Acetone solution for over 5 days.
And nothing.....nada.
The nut for the coupling was already rounded a bit, so I purchased a tension wrench (might have the phrase wrong). I could get no movement with a standard 19mm wrench on the bottom part, tried giving it a bit a bump with an impact hammer at low speed. All that did was cause the top nut to round a bit more.
I'm at a loss. IIRC, the hard line that goes above the rear tire is NLA (haven't checked 928INTL for a used one yet), so any suggestions would be appreciated.
It's not even summer yet and I already feel like this driving period is slipping away from me.
I've got an 85 USA ( my platinum car ) that is being disassembled in the garage.
Based on the map, it isnlt actually not too awful far away from where you are.
Exactly what do you need?
Totally feeling the pain on this.
Hey Ryan, Stan mentioned in a separate thread about using an "induction heater" as a alternate method for heating a coupling in order to silver solder it... so... I did some research on induction heaters. They are kinda pricey (200+) but the main use people report is to heat various fitting to cherry red for removal. Just another idea, but probably a nuclear option at this point.
In this thread, GB mentions that several of the NLA lines are available as upgrades from J2 ...
Clutch hoses. Make a line that will replace the metal line to the slave, to clear lowered pan, or hose to replace stock flexible line.
Oil cooler lines.
Brake line sets.
Fuel lines.
CIS lines/sets. Have all CIS lines to/from WUR, cold start, and fuel distributor.
Transmission lines (auto trans).
A/C line/hose to replace hose under C/D unit.
__________________
greg brown
Again, maybe another "overkill" option at this point. But, I'm starting to take more of a slash-and-burn approach to lots of these hopeless 30 year-old parts.
On a less dramatic note, I'd be happy to send you these wrenches if you think they'd help. They were a lifesaver on those stupid hard brake lines...
@Landseer - on my '82, there's a hard line that runs from where my picture shows (rear of the rear PS wheel well), up to the top of the wheel well, then down to the front side of the wheel well. It terminates at another coupling, so that's the part I'd need if I'm not successful with getting it off.
My brother-in-law are from Elkhart (went to Columbia), and I'm out that way a few times once the weather warms up on my way up to MI.
@Dan - I looked at the induction heater, too, but was scared away from the price and the fact that I just didn't know if it would work. The tools you showed would probably have been beneficial back when the nut wasn't all rounded, but the wrench that I have not gets a damn good clamp on it with still no joy.
I had a similar problem with one of my engine bay lines.
FIRSTLY I will assume NO FUEL PRESENT AT ALL prior to trying the following;
You say you heated the "line"? If so then this will provide no relief as it will only "swell" the thread even tighter.
You need to apply direct, flame heat, I use a butane torch (as pictured) to the LARGE female nut, not red hot though!!! and apply around as much of the outer surface as you can get to, NOTE: it is a fine line between too much and not enough heat, so start at say 20 seconds of heat, all you are trying to do is "swell" that female nut enough to break free of the locked thread.
You will already have the rounded male nut locked in your "vise grips", (that's what we call them down-under) then slightly TIGHTEN the FEMALE nut with your perfectly fitting strong wrench...this will "crack" the seal within the thread itself, you will more than likely feel it give, then unwind the nut and drink beer!
Having said all of that, that male nut is toast now anyway.
G'day Kiwi,
Just gave your suggestion a try as well. Heated for ~20 seconds, had the large nut at around 500F, gave her a slight tightening twist with the 19mm wrench.
And no joy.
Should I try giving her more heat?
(And yes...fuel system has been dry for many months now...)
Also, make sure you are nice and evenly "centred"when you yank on those tools, you need to almost "feel" the thread is perfectly "straight" when you apply pressure, if that makes sense.
Oh you can also apply "cold" to the male end, but seriously I would be looking for another attachment point to attack if it came to that.
I had the same issue on the connection between the hard line and the 'soft' line in the engine bay on my S4 (the supply line to the front of the engine). The 17 mm nut was rounded like yours.
To get it apart I borrowed battery operated compression tool from work (power industry, compression sleeves used for joining cables). Put a 16mm hexagonal die in it and clamped the rounded 17mm nut. Good grip and plenty of leverage, and the nut came undone. There was rust on the threads that cleaned up well.
I filed the nut down to 16mm, because it seemed too difficult to re-do the bubble fare if I cut the line to replace the rounded connection, and replacement of the hard line requires the engine out and rear suspension to be lowered.
About 2000 klm's later there are no problems. I have a set of the fancy spanners shown in Daniel5691's post (what, no chicken). They are a good tool but if the nut is rounded too far, more extreme measures are required.
Last edited by G.P.; 05-20-2017 at 09:04 PM.
Reason: added a couple of words.
I'm not familiar with the line pointing downwards in your picture. What is that line made of, and how does it fit onto the larger fitting that you are trying to undo?
When dealing with stubborn nuts like this, I like to cycle heat and penetrating lube. You could also try grinding two flats on the male nut using an appropriate mini grinder, get a good grip on the male nut and hold it rigid, this will also act as a heat sink for the male nut, then the female union nut moves about that, after direct heating on the female. Get as much leverage as you can. It's possible to re-use the male nut and avoid re-flaring the line this way. Best of luck!
Keep at it...unfortunately a little damage has been done by your efforts but don't feel bad, these things can be hell. For the future, literally weeks of planning have to go into this. First is choice of penetrant ...Fluid film is my favorite. Start spraying fasteners/ fittings ASAP...best to let the fluid film work for weeks on the fuel line fittings. They will typically come apart with wrenches after that.
Whenever I get a new to me 928..I Fluid film any fittings/bolts that I might have to deal with on that car eventually.Heat shields, axles, suspension points, height adjusters, exhaust, brake fittings, fuel fittings clutch hydraulics etc. One can does every fastener/fitting under the car. By the time I get around to a project under there it's like taking apart new threads.
Thanks for all the input, guys. Appreciate the help.
Originally Posted by blueskies
I'm not familiar with the line pointing downwards in your picture. What is that line made of, and how does it fit onto the larger fitting that you are trying to undo?
It goes down to the fuel filter. It has a hard line at both ends, and I *think* it has a rubber piece connecting the two given how it feels. But...the middle part is covered by foam so I don't want to go pulling it back.
When dealing with stubborn nuts like this, I like to cycle heat and penetrating lube. You could also try grinding two flats on the male nut using an appropriate mini grinder, get a good grip on the male nut and hold it rigid, this will also act as a heat sink for the male nut, then the female union nut moves about that, after direct heating on the female. Get as much leverage as you can. It's possible to re-use the male nut and avoid re-flaring the line this way. Best of luck!
I've done quite a bit of heat and penetrating fluids up to this point, but not heat to the degree I was yesterday. I'll go back to using the torch to try to get things hotter and will keep going the lube like you say.
Love the idea of flattening out the nut a bit!
Originally Posted by drooman
Keep at it...unfortunately a little damage has been done by your efforts but don't feel bad, these things can be hell. For the future, literally weeks of planning have to go into this. First is choice of penetrant ...Fluid film is my favorite. Start spraying fasteners/ fittings ASAP...best to let the fluid film work for weeks on the fuel line fittings. They will typically come apart with wrenches after that.
Whenever I get a new to me 928..I Fluid film any fittings/bolts that I might have to deal with on that car eventually.Heat shields, axles, suspension points, height adjusters, exhaust, brake fittings, fuel fittings clutch hydraulics etc. One can does every fastener/fitting under the car. By the time I get around to a project under there it's like taking apart new threads.
I mentioned 2 weeks in my original post, but I'm probably closer to 3 at this point. And I've been diligent. Every day I would re-apply/soak, giving the metal a bit of a tap with a wrench to apply some shock to it. Will give your suggested Fluid Film a try. Gracias for the pointer.
Originally Posted by M. Requin
Another wrench to hold that rounded-off nut - a plumbers basin wrench, mu go-to for problems like this:
05-20-2017, 03:46 PM
Rusted Fuel Coupling Woes - Fixed
