How to remove 'old' brass flare fittings??

D

dansawyer

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The project requires remove several old, weathered, brass flare fitings. I have had success with PB Blaster on steel, however the first 2 fittings I tried failed. The wrench twisted the hex sides.
Is there a solution better suited for brass?
Heat is not a practical option because the fittings are on rubber hose.
Thanks in advance, Dan
 
a picture of the brass flare fittings might help me to understand what your problem is. I can't picture them on rubber hose.
Dave
 
Did you use an open end wrench, which grips only two of the flats? These do not work well on brass fittings.

Usually, if there is a rubber hose, it is best to replace the hose when you unscrew end fittings. In that case, you should be able to use a box end wrench, which would grip all six flats. A 6-point box end or socket would be the best option, but you have to remove the hose from the fitting to get it to work.

There are wrenches that will grip all six points while the hose or tube is still attached, but they are rare and expensive.
 
Provincial said:
Did you use an open end wrench, which grips only two of the flats? These do not work well on brass fittings.

Usually, if there is a rubber hose, it is best to replace the hose when you unscrew end fittings. In that case, you should be able to use a box end wrench, which would grip all six flats. A 6-point box end or socket would be the best option, but you have to remove the hose from the fitting to get it to work.

There are wrenches that will grip all six points while the hose or tube is still attached, but they are rare and expensive.
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Another reason to replace the hose if it's old is the rubber can break down inside. It will flake off and get into places that you don't want it. Get replacement hose, cut the old one so you can get a point wrench or socket on the nut.
 
paradox_pete said:
Called, appropriately enough, "flare nut wrenches". They aren't really particularly rare or expensive.
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"flare nut wrenches" do not grip all six flats/corners. They have a cutout section that allows them to fit past the tube, and that eliminates at least one gripping point. If the hose is left attached, most flare nut wrenches do not have a large enough cutout to pass the hose.

My point was that you need to apply the force to all six corners/flats. Often, when dealing with a difficult brass flare nut, a flare nut wrench merely damages more corners. I know this from experience.
 
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I would like to add that if you are having trouble, get a real name brand flare nut wrench. Bought my kid a parts store flare nut wrench for his 4runner. 12mm I think. It is a name brand you see in catalogs and Amazon. Got lazy and got it out of his wilderness tool kit. It started to round off the brake line fittings. Went and got my SnapOn and it worked perfectly. The radius or chamfer on sides of wrench leave little gripping area. My SnapOn has twice the contact surface. You can heat a brass fitting on a rubber hose and use penetrating oil, just not real hot.
Last resort is to cut the hose and use a 6 point box wrench.
 
Wrenches don't grip on the flats. There is always some clearance so the contact points are at the corners. My flare nut wrenches grab five of the six corners which is better than two. The flare nut wrenches almost always do the job. My nemesis, though, is steel brake lines. Usually, the line and nut are both rusted and even when the nut breaks free, the line turns with it. The result is a twisted line requiring a replacement of the line. Sometimes, with a little gentle persuasion, some WD40 or Liquid Wrench, possibly some heat, and a lot of patience it is possible to break it free but only if Murphy is asleep at the switch.
 
RJSakowski said:
Wrenches don't grip on the flats. There is always some clearance so the contact points are at the corners. My flare nut wrenches grab five of the six corners which is better than two. The flare nut wrenches almost always do the job. My nemesis, though, is steel brake lines. Usually, the line and nut are both rusred and even when the nut breaks free, the line turns with it. The result is a twisted line requiring a replacement of the line. Sometimes, woth a little gentle persuasion, some WD40 or Liquid Wrench, possibly some heat, and a lot of patience it is possible to break it free but only if Murphy is asleep at the switch.
Click to expand...
Amen to that brother!!!! Take it from someone who has been doing this for years.
 
While searching for a flare nut wrench that grabs all six corners, I ran across this. A last resort for stubborn nuts that have defeated all previous attempts. https://mgaguru.com/mgtech/tools/ts108.htm

BTW, I did find the fabled flare nut wrench that grabs all six points. It is a 12 pt wrench which tend to round corners more easily. It only works in one direction , ratcheting in the opposite direction. At least three manufacturer/distributor(s); Proto, Wright, and Snap On.
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