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Brake Line Flare Nut advice needed.........

4.9K views 13 replies 7 participants last post by  heyjude076  
#1 ·
I am currently working on my '64 Tempest and want to upgrade from a single-reservoir m/c to a dual. I found a manufacturer who makes a "bolt-in" replacement set-up consisting of: mastercylinder, pre-formed lines and, new distribution block. Supposedly the new distribution block bolts up to the existing front and rear lines. I have everything loose except for the last flange nut on the distribution block. I have been letting everything soak in PB Blaster for a week and impacting the nut slightly using a hammer and flat-tipped punch. I have the correct flange nut wrench but I am afraid of breaking something if I apply too much pressure. I am also a little leery of using heat for fear of distortion. Any suggestions?
 

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#2 ·
Heat the brass block up slightly to expand it. After it cools apply a little more PB and let it set. When you try to loosen it, tighten it slightly, then try to loosen it. Don't apply constant force in one direction. You will have to move it back and forth. The heat should not distort anything in the brass connector. You have two things working against you. The nut on the line is corroded, and the nut into the brass is corroded. Expanding the brass with heat and working with it, you will have enough flex in the line to break it loose. Then yyou wil have to concentrate on breaking the nut loose from the line. A little more heat concentrated on the nut, and a little more PB on the line to wick back. Patience will get them both loose.
 
#3 ·
You do not need the block ( new one with the kit ) so go ahead and twist. Even cut it off if you have to. Flaring a new line is not a big deal. Double flare tool kits are reasonable and should be in every HOT ROD guys tool arsenal anyway. :D
 
#4 ·
scotzz said:
... Supposedly the new distribution block bolts up to the existing front and rear lines. I have everything loose except for the last flange nut on the distribution block. .... Any suggestions?
Is the last flange nut the one going to the M/C. If it is - your are going to replace it anyways. I would do as described with some heat to the brass. I would cut the line close to the flange nut. Then use a six point socket of the correct size.
 
#5 ·
heyjude076 said:
Is the last flange nut the one going to the M/C. If it is - your are going to replace it anyways. I would do as described with some heat to the brass. I would cut the line close to the flange nut. Then use a six point socket of the correct size.
The last flare nut is on the right side of the block (in picture) and goes to the passenger-side front wheel. I had some problems with the other ones breaking the line free of the nut once I managed to loosen them from the block but everything is loose except for this one. Even with the flare-nut wrench it feels like the nut wants to round-off. The reason I prefer not to break it is that the tight bend leaves little to no room to work. Actually this picture is an earlier shot......I have more of the rust off. I really thought the biggest problem was going to be the bolt that fastens the bracket to frame but that came loose fairly easy. I'll just keep working it using some heat.
 
#6 ·
Also.......it is not that easily accessible..........it is located beneath the steering shaft and the car is fully assembled........This is a shot looking down from the top. The line going to the top of the pic is to the m/c and you can see the steering shaft. The nut I am having difficulty with is the one at the bottom of the block.
 

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#8 ·
Triaged said:
With something that old and in the rust belt I would just rip out all the hard lines are replace them while you are at it.

...wow all those "while I'm at it" really add up :pain:
lol..........you're right and that's the long-term plan.........I actually just wanted to rebuild the mastercylinder, get all the bleeders open (again without breaking anything) and flush the system for beginners. The second part was to convert to a dual reservoir after I located all of the components needed. I already bought the rebuild kit and had all the bleeders opened but then decided to upgrade to a dual reservoir conversion after stumbling upon a complete kit while looking for a replacement master cylinder-to-distribution block line. So I figure, why not just do the upgrade since all it involves is freeing-up three lines into the block. I'm bringing the propane torch tonight or tomorrow and going to apply some heat. I'll get it......I just need to be patient.
 
#9 ·
A brass block is not going to be corroded together with the flare nut. Usually, the nut is corroded to the line.. A common mistake is to try to loosen these fittings with a constant pressure. If you do this the flare nuts go out of round and then can't be removed.
Support the block with a wrench or vicegrip so it can't move. Tap the tube wrench with a brass or hard plastic hammer in the loosen direction. usually one or two hits will do it. Then just a few back and forth turns will loosen it fron the line.
 
#11 ·
dont know what a flare nut wrench is. Must be something plumbers use. Flare nuts are used on copper.
A tubing wrench is a heavy duty six point box end that has a slot cut in it to slide over the tube. The extra heavy side wall of the box end is to prevent spreading when force is applied. As a flare is kinda like a tapered fit, it usually takes a rap or two to get them loose from the seat. Works for frozen bleeders too.
The tubing nut sticking to the line is another issue. usually, they come right loose once the flare is loosened. If it doesn't, I use a short piece if fuel line of the right i.d. put over the line and clamped with a pair of curve jaw vicegrips to hold the line while working the tubing nut loose. Applications of a good penetrating oil will help get it started.
A point of interest. Have the long side of the tubing wrench pulling on the nut rather than pushing. It is less apt to round the tubing nut.
 
#12 ·
Well......................I managed to free up the last nut without having to resort to using heat............I followed 61bone's advice and tapped on the wrench with a hammer................not heavy blows, just moderate and I finally felt it move. The line was frozen to the nut but some more penetrant along with working the nut back and forth and all is loose.

Thanks all!
 
#13 ·
61bone said:
dont know what a flare nut wrench is. Must be something plumbers use. Flare nuts are used on copper.
A tubing wrench is a heavy duty six point box end that has a slot cut in it to slide over the tube. The extra heavy side wall of the box end is to prevent spreading when force is applied. As a flare is kinda like a tapered fit, it usually takes a rap or two to get them loose from the seat. Works for frozen bleeders too.
The tubing nut sticking to the line is another issue. usually, they come right loose once the flare is loosened. If it doesn't, I use a short piece if fuel line of the right i.d. put over the line and clamped with a pair of curve jaw vicegrips to hold the line while working the tubing nut loose. Applications of a good penetrating oil will help get it started.
A point of interest. Have the long side of the tubing wrench pulling on the nut rather than pushing. It is less apt to round the tubing nut.
Flarenut wrenches and tubing wrenches are the same thing also sometimes called a line wrench. Look it up on any of the automotive tool sites. A flare nut is the correct name for the brass nut that rides against the back side of a flare to loc it agains the seat. These are also used is some plumbing configurations as well
 
#14 ·
scotzz said:
Well......................I managed to free up the last nut without having to resort to using heat............I followed 61bone's advice and tapped on the wrench with a hammer................not heavy blows, just moderate and I finally felt it move. The line was frozen to the nut but some more penetrant along with working the nut back and forth and all is loose.

Thanks all!
Glad to read that your perserverance paid off. Thanks for posting your successfull method for others to follow.