Frozen brake line nuts?

[OUTFXD]

Time to rebuild the master cylinder!   Got all the bolts loose except the actual brake lines.  as soon as I put a wrench to them,  I could see the jaws on the wrench flex rater than the bolt showing any sign of moving.   I went to town and got a 3/8 f;arenut wrench.   Put it on. same result. a little more pressure and it starts rounding the nut.   

 

Having just soaked everything down with brakeclean,  I was a leeeeetle hesitant to put the torch to it.  

 

I figured give it a day or two to dry off so I dont burn down my car and put it to the experts.

 

How would YOU go about loosening the nuts?   and on that topic I am not interested in putting damaged nuts back on the car.  and while I am at THAT,  might as well replace all the hard lines sooo... anyone got a good source for brake line kits for our cars? (1946 Plymouth Special-Deluxe with the 218ci engine and a three speed)

 

Edited July 9, 2023 by OUTFXD

[Plymouthy Adams]

as  you going to rebuild this given it is good inside, heating the nuts will not hurt the cast iron cylinder.....you will want to replace the frozen up packing nut and more than not a new line so you will not have to revisit this in short order....stitch in time sort of thing.....or pay me now or pay me later.

[Dave72dt]

Since you're going to replace the lines, cut the line off next to the nut and put a 6 point socket on it.

[Sam Buchanan]

Never use a torch around brake cleaner……it can kill you.

 

https://www.thefabricator.com/thewelder/article/arcwelding/cleaning-material-with-brake-cleaner-before-welding-a-risky-move-that-can-turn-deadly#:~:text=The Safety Data Sheet (SDS,hydrogen chloride and possibly phosgene.”

 

No need to buy a brake line kit. Your local auto parts store has prefabbed lines in various lengths, just put together whatever is needed.

[Los_Control]

Good idea to back off & think about it ..... You add heat to the line & will do more damage to the thing you are trying to save.

 

I would probably try vice grips to get it loose ..... either way may be time to replace the line also & not just repair the cylinder.

 

I have used vice grips in the past & had no issue using it again ..... they worked fine & were beaters with a heater ..... just saying it works.

Up to you to decide what you really want to do.

 

 

[vintage6t]

Soak the threads with penetrating oil. Put the flare wrench on the nut. Then visegrips around the flair wrench jaws to keep them from flexing.  Instead of gradual force, use hard abrupt force when turning the wrench. That should break the not loose.

[Sniper]

6 minutes ago, vintage6t said:

Then visegrips around the flair wrench jaws to keep them from flexing.

 

After 58 years, I just figured this trick out this summer, lol.

[Los_Control]

Hot Dog, maybe I just learned something new  

[FarmerJon]

I have dealt with this quite a few times.

My procedure is this:

Clean off bulk grime with wire tooth brush. 

Spray with PB blaster, Kroil, or similar.

Try with correct size line wrench- (quality tools matter here) I will usually try to tighten the nut (less than a 1/8 turn!) first to break it free from rust.

If it seems stuck, stop before you round it off. Grab it gently as possible with vice grips,  and try the tighten/loosen again. Sometimes the line sticks inside the nut, so beware. I will often put a second small pair of vice grips on the line besides the nut to work against twisting it off.  If it still won't budge, stop before you wreck it.

With a propane or Mapp Gas torch, heat the nut and line up and let it cool several times. When still warm, spray it with your PB again. 2-4 cycles usually gets it done. You aren't trying to get it glowing hot, but too hot to touch, probably 400-500* or so.

Once cool, repeat the vicegrips. 

If it hasn't gotten loose after all that, it isn't likely to come out peacefully, so cut the line and use a easy out on a work bench or vice.

 

On farm beaters, I had OK luck reusing lines that had been heated, usually ones that were in too bad of shape don't survive the process. 

If your lines are very old, it would be wise to run new ones. I would rent a bender and flare tool from your parts store, by a roll of line and a pack of the right size line nuts. Watch a handful of YouTube videos and get it done. 

 

 

[Dave72dt]

2 hours ago, OUTFXD said:

Time to rebuild the master cylinder!   Got all the bolts loose except the actual brake lines.   I am not interested in putting damaged nuts back on the car.  and while I am at THAT,  might as well replace all the hard lines 

 

Cut the lines, remove the master, put in  vise, 6 point socket on the nuts and remove from master.  You can do the same thing at any of the other fittings, unions, wheel cylinders, etc.  You're not trying to salvage used nuts or the line.  Brake line replacement should be an automatic on these old cars. You'd have to cut the line to get even the used ones off to reflare for a new nut.  If you snap the nut off with the socket, you probably would have by heating, vise grips and other methods also.

 

I used to fiddle with the nuts too.  Most of the time the lines were not worth the risk of using over.

[Ivan_B]

+1 for cutting the lines and redoing everything properly. Chances are, these old lines will not seal properly anyway, and you'll have to gorilla-tighten the same nuts trying to make it work when you put it back together. Use some copper/graphite grease on the new nuts, for next time

Edited July 10, 2023 by Ivan_B

[Bryan G]

I was surprised the difference a good quality flare wrench can make. My first one didn't seem like junk (from NAPA, made in Taiwan as I recall) but I kept having trouble. Then I picked up a used Mac and it made all the difference.

 

On another car I had I bought pre-bent lines from classictube.com and they worked well, though I paid someone else to install them. (I chickened out!) But on my current car I bought sections at the local parts store and put them together. Nickel-Copper is the way to go. I didn't have to use any tools for bending. Very user friendly.

[kencombs]

4 hours ago, Sam Buchanan said:

Never use a torch around brake cleaner……it can kill you.

 

https://www.thefabricator.com/thewelder/article/arcwelding/cleaning-material-with-brake-cleaner-before-welding-a-risky-move-that-can-turn-deadly#:~:text=The Safety Data Sheet (SDS,hydrogen chloride and possibly phosgene.”

 

No need to buy a brake line kit. Your local auto parts store has prefabbed lines in various lengths, just put together whatever is needed.

I never buy the clorinated brake cleaner.  All the brands I have available locally are clearly marked as to clorinated or non.  the non isn't quite as effective as the nasty stuff, but I use it anyway.  Safety first ya know!

 

About the flare nut wrench, this is one of the few places that I think Snap-On prices are warranted.

Edited July 10, 2023 by kencombs

[Ivan_B]

15 minutes ago, Bryan G said:

Nickel-Copper is the way to go.

It sure is! You can also buy/borrow the flaring tool and cut your own lines exactly to OEM specs

[TodFitch]

As mentioned above by @Dave72dt cutting the line and using a 6 point socket to remove the tube nut is a good way to go.

 

One thing I didn’t notice in the other replies: conventional brake fluid absorbs water and as a result steel brake lines can rust from the inside out. If there is enough external corrosion to freeze up the tube nuts then it is very likely that the steel tubing is also unsafe due to thin spots from internal rusting.

 

Making your own brake lines is not that difficult even with an average flaring tool and a little practice. I used the copper-nickel alloy tubing mentioned above by others, it is pretty easy to work with.

[Local2ED]

I use a 4" Rigid pipe wrench on the flare nuts to break them loose.

Never had any luck with vise grips.