Help replacing rear brake flexible hose….
 

I’m at a loss - any advice would be greatly appreciated!!!!!!

Re: Help replacing rear brake flexible hose….
 

Are you looking for part numbers or a how to replace the hose?

Re: Help replacing rear brake flexible hose….
 

How to replace it. It would also be beneficial if I specified that my truck is a ‘67 GMC…(I‘m an idiot for failing to do that).

Re: Help replacing rear brake flexible hose….
 

Is your truck a c15 -1/2 ton or a c25 -3/4 ton? I'm not sure it makes a difference on the GMC's. but post it up anyway.

EDIT: Also whether it has leaf or coil springs in the rear....

The first thing you will have to do is locate a brake hose for it. If your local auto parts store doesn't have one listed Rock Auto has a few of them. It would be listed as a "rear center" brake hose. The parts store will have to know all of the specs for your truck to be able to look it up.

Re: Help replacing rear brake flexible hose….
 

Soak those joints in penetrant for as far ahead as you can. Use a decent set of line wrenches.
That 90* bend at the end of the front->back hard line is kinda fragile, and that nut can be locked up to the hard line so it'll twist the tubing
...so, IMHO your best bet is to hold that nut immobile and see if you can get the end of the soft line to move a tiny bit o break it loose from the "wrong" side.
If that doesn't work, you'll just have to do your best not to mangle the hard line
The other end is a block that's pretty easy to immobilize

Re: Help replacing rear brake flexible hose….
 

I just finished doing one. Biggest thing is to start appying a good penetrating oil (WD 40 is not a good penetrating oil). If you have a few days, all the better, keep applying at least once a day, more is better. Then use good line wrench, and keep after it. I have found a good homemade penetrating oil is a 50/50 mix of ATF and acetone, but it takes some time, the acetone thins the ATF and carries it in.

Re: Help replacing rear brake flexible hose….
 

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To add to what the others have said, here is how I get brake lines loose. Heat the flare fitting on the metal brake line with a propane torch, let it cool a bit and then spray some penetrating oil on it. Do this two or three times to break the rust bond on the fitting and use a brake line wrench to try and break the fitting loose. (do not try to use an open end wrench on it) Don't just put the wrench on it and crank on it cause you will round off the flats on the flare nut. Try to loosen it, then try tightening it. Keep going back and forth until it starts moving. Once it starts moving keep turning back and forth a little more each time until you get it so it turns easy, then unscrew it. If the metal line is really rusty it may twist off anyway but all you can do is try.

Re: Help replacing rear brake flexible hose….
 

Listen to Lockdoc about the propane torch, it will make your life so much easier. I've done a few of these and don't even try to break them loose anymore without using the torch first.

I discovered earlier this year my old craftsman line wrenched were not that great. I bought a couple used snap on ones from ebay and they are so much better.

Re: Help replacing rear brake flexible hose….
 

Thanks for the replies!

LockDoc said “ Don't just put the wrench on it and crank on it cause you will round off the flats on the flare nut.”

Unfortunately I’ve apparently already done that-I assume and hope that using heat, vice-grips, and Aerokroil I should successfully get it off?

Re: Help replacing rear brake flexible hose….
 

You should be able to get it off with the grips after heating it a couple of times and spraying it. Be sure and let it cool before using the grips on it or you may crush the nut and then it will bind on the metal line and won't turn..

Re: Help replacing rear brake flexible hose….
 

If you didn't round off the fitting, carefully file the sides flat again and next time use a flare wrench. heat, penetrating oil...repeat

I got these brake line wrenches on ebay several years ago. They were the same as the exploding wallet Snap-On ones ($250 IIRC) for $50. It appears they are not available anymore but for me after doing all that was suggested, they did the trick. Using a breaker bar which the tool accepts gave enough leverage and the tool design clamps tighter with the more effort put on it

Worst case, you cut soft line and put a socket over fitting while securing the hard line fitting

Re: Help replacing rear brake flexible hose….
 

Pay close attention to the tubing inside of the fittings so you don't twist the tubing when turning the fitting. Also too much pressure with vice grips can crush the fitting.

If it starts to deform, stop and reapply the pentrating oil to soak again. After an hour or so heat and apply pentrating oil again.

You want to avoid the picture below.

Good luck.

PS when I found this fitting on my Burban (thanks to the PO) I just cut it off and replaced the line. There was no saving it.

Re: Help replacing rear brake flexible hose….
 

If it's rounded and a wrench won't work, try a Visegrip like this:

Re: Help replacing rear brake flexible hose….
 

That looks good!!!

Re: Help replacing rear brake flexible hose….
 

At that point my tendency would be replace the front-to-rear brake line with a pre-bent one available from Inline Tube. OE steel (not stainless steel), and pay attention to the vendor listings about leaf spring or coil, 2 wheel drive or 4 wheel drive, short bed or long bed, etc. I was struggling with taking loose that joint, and went with replacing the hard lines. That particular hard line is probably the easiest one on the truck to replace.

Re: Help replacing rear brake flexible hose….
 

I've got three sizes of those. They work well. They're also my go to pliers for wire wheeling bolts on my bench grinder.

Re: Help replacing rear brake flexible hose….
 

I've had good luck clamping my cheap line wrench with vise grips to flex the end of the wrench tight on the line fitting. Can be a challenge in tight spaces though.

Re: Help replacing rear brake flexible hose….
 

Finally got it off without deforming or tearing anything up thanks to all the advice regarding applying heat and Aerokroil several times over the last few days. I really appreciate all the advice - I should have posted the question BEFORE I started screwing things up.