Was preparing to take off my single-pot stock MC to finally upgrade to the dual-chamber Raybestos.

Tried loosening those darn threaded flare fittings that screw into the junction block, since I bought a new block that will replace the original.

Of the four threaded fittings that screw into this block, one is the 'original' solid brass fitting that happens to be a larger (and much more practical) hex size. THAT one (of course) broke loose without too much problem.

The other three fittings are newer, and they look like brass but they're not: they're steel or something else magnetic. They are extremely soft metal. I had to replace all my brake lines back in 2010. The guy who replaced all the lines for me must have tightened these buggers down hard. I'll be damned if I didn't manage to easily round off a couple of these pseudo-quality fittings from my gentle but firm hauling on them.

I had soaked them in p-blaster for a couple days before putting a wrench to them. I even tried 'tightening' them first before loosening them but now I don't know what to do. How do people get these fittings loose without destroying the brake line in the process? I'm ok with replacing some short sections of front line, but the minute I destroy the nut/fitting that holds the rear brake line to the block, I'm having to replace a large, long section of brake line that I'll have to re-bend in all the right places and flare. I really don't wish to have to do this. I can't believe how difficult these stupid flare fittings are being The metal is so cheap.

What do people suggest I do?

im assuming you are using a line wrench? when they dont work i use vise-grips. grab it hard enough that you are not squishin the fitting but firm enough to make sure you are getting a good bite and not just going to completely round them off. if you sqeeze it to much you will lock the line in there and wont be able to get the wrench back on it. just use them to break them free not to back them out all the way. im also usually not to worried about messing up the lines because when i am undoing them i am usually replacing the lines anyway.

To prevent wrecking line, watch the line closely while turning fitting
and stop if line starts to twist. apply little pb oil in hole where line
goes into fitting. allow to soak in, not too much if goes into brake fluid
can swell seals cups.

there is a tool vise grip wrench, similar to regular vise grip, but
has flat half hex jaws to grab on to bolt like a wrench, i used
the small 6 inch one and manage to loosen a rounded fitting.
on you tube one person used regular vise grips.

I use a combination of tools, and usually end up destroying a nut or line, especially when they have been on there for years!

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1964 Dart GT

my method is much like a few posted.
Spray the bajeezuz out of it with PB blast.
I then use a form of Vice Grip depends on how I can get to it really, but I do use Vice Grips.I "tighten" it just a tiny smidge.Then loosen it a bit.I guess a little back and forth so the line wrench can work without twisting the line.

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Wife's: 64 Valiant
My: 70 Road Runner, 67 Barracuda, AND the 62 Valiant drag car!!

You assumed wrong. I've been using a simple open-end wrench. The amount of 'rock' they have on the nut was really too much for me, but I didn't see what else I could use.

Have seen line wrenches before but didn't know their application. I'll have to pick up one and give it a try.

I always use line wrenches, and when that fails I use a hacksaw and a tubing flaring tool.

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Casually looking for a Clifford hyperpak intake for cheap.

ill admit i dont usually bother with them either. if you dont have a set yet make sure you get a good one. the cheap ones will rock like you said. or they will spread and just round off the fitting.

If none of the above works, cut the tube close enough to get a socket over the stuck fitting, it will come free. You will need to stabilize the junction block with a wrench being careful not to deform any of its female ports. Stuck corroded brake fittings are a way of life in Maine.

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

Ditto to everything that's been said so far.

If you do end up having to cut the lines, do you have any slack to just re-flare the ends? I've seen actual brass line fittings at auto parts stores before. The tool for double flaring isn't that expensive, but doing it can be tricky. You may want to practice on a scrap piece of tubing before trying it in a cramped space on your actual brake lines. Screwing up and cutting it off again costs you more slack that you might not have.

Just double check that you've actually put the end fitting on before you do the flare. Not like I've ever screwed that up or anything... cough cough.

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Somehow I ended up owning three 1964 slant six A-bodies. I race one of them.
Escape Velocity Racing

Ok, some success.

After three trips to Sears and a couple different recommended solutions (first the line wrenches didn't work because I'd rounded the nuts too much, then I had to use notched vise grips, which did work), I finally managed to get the new junction block properly installed. Joy of joys, I also managed to avoid destroying the nuts and line, so all I had to do was connect them up. Excellent.

Now, please look at the photo below and advise. I cannot pull apart the old push rod from the MC piston. I have disassembled it further than I show below (I've removed the retainer, spring and pulled up the rubber boot to expose the push rod sticking into the piston, yet even when I pull hard, the rod doesn't want to pop out. I've pulled as hard as I can and no luck. Should it? How have other people separated the two? In the new Raybestos MC, I can feel with the end of my pinky finger that the internal piston 'cup' that holds the end of the pushrod has some kind of a ridge and that's what's probably holding the pushrod to the old piston. How can I separate?

Should I use the old flange, spring, rubber boot + retainer on the new Raybestos MC? If I do, how does all of this stay in place? There are no screw holes to keep the flange in place so I'm confused about which parts I should be using and which ones should be discarded. Am I missing any spring and boot parts for the new MC pushrod-to-piston junction point?

Thanks all.

PULL HARDER! No, Really, pull harder, it will come out. I had to put the piston end in a vise and a screwdriver through the looped end to get mine apart. There is a rubber cap on the end of the rod you will be replacing. I also had the issue with no screw holes in the master cylinder for the boot. I Duct Taped mine to the Firewall to hold it in the correct place, with the rod already attached to the brake pedal. It sandwiches between the firewall and the master cylinder. BENCH BLEED YOUR MASTER CYLINDER! I also noticed that when I bought my master cylinder for the disc conversion, it has the holes for the boot, where the drum-drum one didn't??? Hope this helps.

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1964 Dart GT

While the M/C is in the car I pull up on the brake pedal until the rod comes out of the back. It is much easier while it is bolted in place.


Rick

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

I never bothered with the boot. Any I pulled out were rotted and crumbled and didn't have replacement so just did without.

For the rod - I've used two methods. Assemble everything back in the master cylinder. Put the rod in a vice with the cylinder pointing to the ground or at least sideways. Then you can beat on the cylinder flange with a sledge.

Alternatively - put the piston in a vice, then grab the rod with pliers. Heat the piston with a torch. Eventually the rubber piece interlocking the rod and piston will give way. You can also cut a slot the length of the piston with a dremel or cutting disc. Go little at a time until you break through the piston but not so deep to nick the rod. Do it again on opposite side of piston.

There is a piece of rubber locking the rod to the piston. It's maybe 3/16" wide, with hole in middle. A new one should have come with your new master. The ridge you felt in the piston - it sits in that ridge. There is also a corresponding ridge on the rod. The outer diameter of the rubber is just slightly over the inner diameter of the piston. When installed, it compresses to let it get in the piston, then expands into the groves securing everything.

This is a safety. In car, the only thing preventing the pedal from moving backwards (say you get your foot caught under the pedal without realizing it...) is the breakable plastic brake light switch. If it moves out far enough the rod will come loose of the piston and, well, uhoh.

If your going to use Rick's method remove the switch. His car may have the switch in a different place.

Ok, pulling HARDER now.

On the boot, that's stupid. So people who have this MC don't use a flange, boot, spring and retainer, there's no need?

This rubber piece you're talking about that interlocks the end of the piston in the cup - is that a piece I can go buy, or is there a simple homemade version? My new dual-chamber MC did NOT come with one.

So see that rubber 'cup' between the end of the piston and the flange cover - do I re-use that cup on the new setup? Here's an image of what I'm asking: