changing rubber brake lines

[Doug Steinel]

Having trouble getting the fitting loose from the hard brake line so I can change the rubber ones. Whenever I use my flare nut wrench to loosen the fitting, the hard brake line wants to turn with it. I am afraid of breaking the hard line. Can I heat up the fitting with my torch so it will expand and break free? Any other suggestions?

[Bill Verburg]

Use 2 wrenches

[vash]

are both ends of the rubberline frozen up? if not, disconnect the easy side first and then spin the entire hose off the bad side. pieceocake!

[Early_S_Man]

Brush/dribble/spray some 9% pickling vinegar over the junction of the fittings, let set 10 - 15 minutes, then repeat ... after an hour you may apply torque with two flare-nut wrenches, and hopefully the corrosion will be loosened by then!

[greglepore]

You can cut the hose if they're both frozen, and yes, you can use heat if you don't have another alternative.

[sundaypunch]

Hit them with some penetrating oil a week ahead of time and then a couple more times before you try to break them loose. I like PB Blaster and Kroil. Don't mess with old nuts / bolts / fitting without soaking them first.

[yann-olivier]

Hello,
I've just had the same problem 2 days ago. What i did was to cut the rubber line in two parts to first allow me to unscrew them and separate them from the hard line without twisting the hard line.
Then, i used a blowtorch to heat the fitting of the hard line. it expanded and so became a bit free around the hard line. After that, as the fitting was unfrozen but not totally free, i had to make it turn step by step with a wrench, putting grease to lubricate it. Lot of patience needed, but at the end it was succesfull !

[sundaypunch]

I believe brake fluid is flamable

[toolman]

All of these parts are plated to resist corrosion, once heated, will corrode even faster. My frozen line was at the caliper so I bought 2 small metric lines, cut them to fit, and used an ISO flare tool to replace them. OTC makes a nice one that sells for about $30, and Imperial makes a nice tubing bender to get those nickle sized curves right.

[yann-olivier]

in fact, yes, brake fluid is flammable but if you take care, it won't burn. Moreover, once the rubber line is away, you'll only have to heat the hard line end. My solution is perhaps not a very academic one but if you are "trapped" with these frozen fittings, it's a way to achieve your work...

[Jdub]

PBBlaster or equiv. over time, tap the fittings gently, and also try to tighten them a bit, then apply more PBBlaster. The tension on these thread is on "one side" of each thread -- tightening them up will pull the threads away from their current seating and permit the chemicals to get into the areas it needs to. The tightening you apply will not actually move the nut, but will cause a detensioning that will help the process.

Gently, two good, solid flare wrenches that seat firmly. Apply steady pressure. Use a small cheater bar only as a last resort.

John

[jazzbass]

Originally posted by yann-olivier
Hello,
I've just had the same problem 2 days ago. What i did was to cut the rubber line in two parts to first allow me to unscrew them and separate them from the hard line without twisting the hard line.
Then, i used a blowtorch to heat the fitting of the hard line. it expanded and so became a bit free around the hard line. After that, as the fitting was unfrozen but not totally free, i had to make it turn step by step with a wrench, putting grease to lubricate it. Lot of patience needed, but at the end it was succesfull !

If the flare nut on the end of the hard brake line is frozen to the line itself, the method yann-olivier describes above is the only way I've found to solve this problem. PB Blaser does not work - even with letting it sit for a week and spraying everyday. BTDT.

If the problem is the threads of the rubber line are frozen to the threads of the flare nut, you may be able to use PB Blaster and two wrenches to solve this problem. Just be careful to hold the flared end still and don't twist the hard line.

Do make sure when you turn the flare nut on the hard line that it is turning freely - these lines are a copper alloy and will shear quite easily. Ask me how I know.

[juanbenae]

easlyS,, is that a martha stewart solution for stuck fasteners? i love it!

[Gordo2]

Doug,

If you are removing the caliper, I found it easier to break the line free once I pushed the connector out of the retainer. Not sure if you are working front or rear or what year your car is...

I had to force the fitting out of the retainer (tapped it out with the long extension and a hammer). Once it was out I could get tools on both sides and hold it steady to crank on it with my flare wrench and an open end on the other side.



Hope this helps, best of luck!

Gordo

Note the liberal application of PB blaster.