Replacing the rear brake lines

[p7387]

87 2wd short fleet

My rear brake reservior keeps loosing fluid, i find evidence of fluid loss around a section of rusted rear brake line under the bed area, given its location i cant see the moisture logically coming from something else.

This will be my firs time attempting this sort of job
How are these brake lines sold? Are they pre bent or is it something i will need to fabricate myself
Will i need any special tools, and most important could someone offer any pointers as to proceedure.

Thank you

[Irish_Alley]

ok lets start with this. if you panic brake with just sitting there you might blow your bad spot out also if you can get someone to press on them you might see it drip out. also look on the inside of your rear wheels and see if you see any fluid running down them (might be a wheel cylinder). but if all else fails you have to cut out the bad pipe or replace it all by buying a roll $25.00 or pre-bent front/rear 2 pieces for about $90.00  3/16th" should be your size
you can cut out the bad pipe with a pipe cutting tool then it strait.

next would be to cut your new piece to fit (tip: brake lines come in a role or various pre-cut lengths with fittings installed and double flare ends) or cut your old brake line to fit your new piece. 

BIG TIP PUT THE NIPPLES IN PLACE BEFORE YOU FLARE THE ENDS. then use a flaring tool to double flare then end (there are instructions with the tool) autozone will rent the tool for $30 you get that back one you return it. just make sure it isnt broke and the cone spins freely.

you have to make sure your ends you cut are straight for the flaring tool to cut right. put it all back together and bleed your brakes.

[jarhead76]

take your time.  its not hard to mess up a double flare.  it took 3 tries to get it right on my 98 GMC sierra. i jsut could not get a good seal.

[Irish_Alley]

had mine leak a couple times, the second time i had to replace the brake line. (first time it only took one time with no leaks) then i just said screw it and replaced the whole line

[Captkaos]

IF you need the whole line, Classic Tube and Inline Tube make them prebent.

[p7387]

Thanks

I see no evidence of fluid at the back of the rear wheels. Given the overall fair/poor condition of the line replacement would seem a better option.

Thanks for the flare explanation and tips irish, i get the theory but i will be able to grasp the process better if i could see a video of some sort, i ill look for one on youtube, this is one of those things for me that will absorb better if i see it.

Is bending and routing tubing a big ordeal, and will the pre bent be worth the extra money to avoid potential headache?

As far as tools
I need a good set of line wrenches, are the craftsman good enough?
Also is it worth purchasing the flaring tool?

Thanks

[frotosride]

Just a little more advice. While you got the brakes down I would recommend replacing the wheel cylinders at the same time. Especially, if it has been a long time of you don't know the last time they were replaced. I had the same issue and as soon as I filled my rear part of the resivoir and the wheel cylinders saw full system pressure, they popped!! I was upset but not surprised at all. Besides that new ones are only like $8ea. just take one off first and take it with you because there are different bolt patterns that will not work with your truck. Good luck and if you need any help just hit us up.  Oh and a little known fact about double flairs, when installed for the first time you have to tighten and loosen them a few times to get them to seat properly or the will leak 9 times out of ten. Sometimes you get lucky and they work the first time with out tightening and loosening them but its easier in the long run to do it while you are down there.

[bd]

...Is bending and routing tubing a big ordeal, and will the pre bent be worth the extra money to avoid potential headache?

As far as tools
I need a good set of line wrenches, are the craftsman good enough?
Also is it worth purchasing the flaring tool?

Bending steel line involves a learning curve that can be frustrating at first.  But, you get the hang of it as you gain experience.  The same applies to double flaring tube ends.  Rest assured you'll make mistakes.  We all did during our early attempts.  You may even waste a little material.  But, it doesn't take long to become a pro.  For my personal use, I would purchase prebent lines only if migrating to stainless steel, or if there were many complex bends and I was working within a tight timeframe.  If you look forward to a doable challenge, fabricate your own.  If you frustrate easily, purchase them prebent.

Craftsman line wrenches are fine.  I recommend 6-point flare/open-end combination wrenches.  If money is tight, purchase them individually in various sizes as you encounter the need.  By far, the most commonly encountered sizes are 3/8" (brake lines), 1/2" (trans cooler lines), 9/16" (brake M/C lines), 5/8" (fuel lines), 3/4" (A/C lines and backup wrench) fractional and 10mm (brake lines), 16mm (P/S lines), 18mm (P/S lines) metric.  Gradually, you'll encounter the need for additional sizes, both fractional and metric.

A quality 45° double flaring tool, compact tubing cutter, and tubing bender are essential repair tools, if you expect to do any line work that requires fabrication.  You'll also need a flat 8-10" mill file and small diameter taper ream.  Forming double flares is a two-step process.  Tubing preparation and the initial flare are crucial to proper flare formation and a leak free connection.  When properly formed, a double flare will seal easily without excessive tightening.  The most common error made by beginners is flaring the end of the tube before slipping the fitting onto the tube - that results in a BIG OOPS and a reddish glazed stare.   

When repairing brake lines, DOT requires double flares (or bubble flares) for all line connections.  The double flare requirement also applies to flared fuel lines out of necessity, since leaks can be catastrophic.

[Captkaos]

I had to bend all new lines for my R10 with the LS and Blazer tank.  It was a pain.  Cost wise, it was about the same price as replacing all the lines on the rear of a Blazer I fixed.

[p7387]

Thanks for the detailed explanation bd
I sort of figured it was a involved process that had some sort or learning curve when i saw the price of the lines from the above mentioned sites, 200-300 for prebent vs. $25 for a roll of tubing, there must be some logical reason for the cost difference and the fact that a prebent tube market exists.
That said if i could work in a comfortable garage with the bed off or had access to a lift i might give it a try, but unfortunatly those arent my working conditions.

This is a driver truck so i dont need anything fancy, just reliable good quality.
Are the prebent from any company pretty much a direct accurate fit or are some better than others?
And will the prebent with the fittings attached reduce the likelyhood of leak scenarios described above? Also as i gradually start to replace worn out parts what other areas will i encounter this sort of tubing issue on (fuel lines?)

[Brady]

I noticed that no one recommended the nickle-cu alloy.  A mechanic told me that is what he uses and it is very easy to bend.  Any thoughts on that?

[bd]

I noticed that no one recommended the nickle-cu alloy.  A mechanic told me that is what he uses and it is very easy to bend.  Any thoughts on that?

As federally mandated, any brake lines for use on public streets and highways require DOT approval.  That stated, cost is similar to steel, while handling is easier, and corrosion resistance seems significantly improved. 

In the Western US, exotic lines generally are unnecessary.  But, in the remainder of the Country where winter roads are abused by salt, added corrosion resistance would be of great benefit.  Nevertheless, in spite of "rust-proof" claims, copper-nickel alloy is not impervious to corrosion.  On the other hand, the fittings easily could become the weakest link.

[solve4x]

I'm planning to use the poly armoured lines in my salt-soaked climate....they're fairly cheap at autozone, and supposedly easy to bend.  The video makes it look simple.

 http://www.autozone.com/autozone/accessories/Miscellaneous-Repair-Parts/Brake-Line/_/N-2687

Anyone have any experience with them?