# Replacing old rusty brake lines

**URL:** <https://community.cartalk.com/t/replacing-old-rusty-brake-lines/18613>\
**Category:** Maintenance/Repairs\
**Created:** [August 24, 2008, 6:43pm UTC](https://community.cartalk.com/t/replacing-old-rusty-brake-lines/18613 "2008-08-24T18:43:00Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![AndyB1](https://avatars.discourse-cdn.com/v4/letter/a/ac8455/32.png) [@AndyB1](https://community.cartalk.com/u/AndyB1)\
**Post date:** [August 24, 2008, 6:43pm UTC](https://community.cartalk.com/t/replacing-old-rusty-brake-lines/18613/1 "2008-08-24T18:43:00Z")

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I am replacing a failed brake line on an old car. Any tips for loosening old rusty lines, other then soaking in wd-40? and saying a prayer? Can they be heated up a bit?

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**Author:** ![Constantino\_Tobio](https://avatars.discourse-cdn.com/v4/letter/c/edb3f5/32.png) [@Constantino\_Tobio](https://community.cartalk.com/u/Constantino_Tobio)\
**Post date:** [August 24, 2008, 6:53pm UTC](https://community.cartalk.com/t/replacing-old-rusty-brake-lines/18613/2 "2008-08-24T18:53:08Z")

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WD-40 is perhaps the single most overrated product known to man. Repeat after me: WD-40 is not a lubricant, it is a solvent. While it has some lubricating properties, they are quite short-lived, as the lubricant in WD-40 dries off after a couple of weeks, leaving a gummy residue of worthlessness.

What you want is find a product called PB Blaster. Home Depot carries it, along with many chain auto parts stores. I have had nothing but success with this- including undoing the brake lines from a '73 VW that had been on there for 33 years.

What you do is spray the fitting every day for about a week. By the time the week is over, it’ll break free.

Also, get yourself some flare-nut wrenches. You will be very unhappy when you round off the flare nuts when you use an open-ended wrench, guaranteed. A flare nut wrench will do a much better job undoing these nuts.

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**Author:** ![AndyB1](https://avatars.discourse-cdn.com/v4/letter/a/ac8455/32.png) [@AndyB1](https://community.cartalk.com/u/AndyB1)\
**Post date:** [August 24, 2008, 7:35pm UTC](https://community.cartalk.com/t/replacing-old-rusty-brake-lines/18613/3 "2008-08-24T19:35:42Z")

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Thanks I will try the PB Blaster on this 38 year old car …

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**Author:** ![oldschool](https://avatars.discourse-cdn.com/v4/letter/o/e19adc/32.png) [@oldschool](https://community.cartalk.com/u/oldschool)\
**Post date:** [August 24, 2008, 10:48pm UTC](https://community.cartalk.com/t/replacing-old-rusty-brake-lines/18613/4 "2008-08-24T22:48:04Z")

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If this brake line ends at a wheel cylinder check if its possible to loosen (and remove) the bleeder screw.If the bleeder is frozen or you break it off the points that need to be un-frozen will change,as you will be replacing wheel cylinders also.

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**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\
**Post date:** [August 24, 2008, 10:53pm UTC](https://community.cartalk.com/t/replacing-old-rusty-brake-lines/18613/5 "2008-08-24T22:53:05Z")

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When I get into these nasty jobs, what I do is cut the line at the fitting. This way you’re able to use a six-point socket to remove the fitting. And yes, you can use a propane torch to heat the fitting. Only when doing this, don’t try to remove the fitting right away. Instead allow the fitting to cool back down before attempting to remove it.

Tester