Fuel line flare nuts stuck.....am I doomed?

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little1406
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Fuel line flare nuts stuck.....am I doomed?

Post by little1406 » Tue Apr 30, 2013 5:25 pm

It's been while, gang. I got my CBC Roosa Master injection pump rebuilt by some local folks that knew all about it and started installing it today. It went back on OK but there is a troubling issue:

When I loosen the flare nuts that connect the fuel line to the injector nozzles, the nut and line turn together....instead of the nut turning and the line staying still. The nut and fuel line have rusted/stuck together. I got the nut loose from the mating nut thingy on the injection nozzle OK and I even tried the usual back-and-forth twisting of the flare nut w.r.t. the fuel line a lot, even twisting the line itself slightly each time but 3 out of the 4 nuts won't break loose from the lines.....

Any suggestions? Is this common? Can I just snug them back onto the mating nozzle nuts and try to fire up the engine, maybe with extra batteries to crank the thing for several minutes?

Thanks in advance.
Scott Little
Dale TX

JD 450 w/ backhoe attachment

KenP
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Post by KenP » Wed May 01, 2013 4:10 am

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MarkW
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Post by MarkW » Wed May 01, 2013 11:35 am

A time consuming but pretty reliable approach I have used numerous times in this situation is to remove the entire line and then unscrew it, and usually a few taps on the bottom of the flare nut with a small hammer will break them free disappointingly easily.

If you have the time, for example if this is a several weekend project for you, a thorough de-rusting with something like naval jelly and a toothbrush, then clean and follow with a penetrating oil and gentle heat, then some more penetrating oil the next day can help.

If you are in a hurry and desperate with no other choice, wire brush and oil all over on the fitting and then hold the line with a tube flaring clamp about 1/8" above the nut, then use a wrench and apply force and copious prayer at the same time. I hesitate to suggest that however as I have certainly sheared off my share of flared fittings over the years so if at all possible I suggest removing the line and tapping the nut back to break the bond.

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MarkW
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Post by MarkW » Thu May 02, 2013 11:28 am

I just had this thought, might as well try it and see if it might work for you but to be honest I've never done it myself-

Put a tube flaring clamp above the nut like I mentioned above, then apply a small amount of pressure to the flare nut while rapping the clamp with a small hammer, it might be enough to break it free (or simply break it, LOL). Remember to use penetrating oil, it is your friend.

little1406
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Joined: Tue Dec 04, 2012 6:46 pm
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Post by little1406 » Fri May 03, 2013 10:54 pm

Thanks for the advice, gang. KenP's came in first so I tried the heat method first. Since the 450 is way out in the field and I don't have AC power out there, I used a propane torch on the flare nuts. It only started a small fire once, which I was able to easily extinguish. Two of the three stuck nuts came loose almost instantly with the application of mild heat. The last one took repeated heating/cooling cycles and I ended up scorching the nearby rubber return line that runs from injector to injector....but she finally came loose....! Thanks, KenP....!

I charged up my battery, loosened all the flare nuts and cranked until I saw diesel fuel leaking out from two of the four lines. Then I tightened them all down securely and cranked some more and she fired up nice and easy. After a few seconds of irregular running, she settled down and ran nicely. Whoopee. This thing is working again!

Ken, I agree that the CBC pump is a reliable unit. This old pump is likely 45 years old and still mostly good. When I took it in for rebuilding, they warned me that parts were scarce. I responded by offering to make or fix anything that they couldn't readily obtain and, sure enuf, they called me a day or two later and asked me to come look at what they'd found. Well, the throttle lever on the pump rotates a gear that runs in a little odd-shaped housing that is attached to a tube that runs into the pump body. There's a rack inside this tube which is moved forward/backward by the throttle motion and that's what moves the metering valve back and forth in the pump.

The throttle gear housing was apparently silver-soldered to this tube at the Stanadyne factory and, after 45 years of stress, the solder finally broke. Thus the rack was no longer positively driven by the throttle gear and there was slop in the system, which explains why my governor sorta switched from working to not working as those things slid around in there.

They asked if I could resolder that. I said yes and took it home. Turns out the gear housing thingy is a powder metallurgy part. It just looked that way to me at first glance but it was confirmed when I started heating it with my torch to re-solder it. Jets of pressurized diesel fuel came squirting out of the pores in that powder-metallurgy housing here and there and, of course, caught fire under the acetylene torch flame. Minor excitement, no harm done.

Anyway, I got the thing nicely soldered back in place, cleaned it up real well, and took it back to the injector shop. They liked it, and put the pump all back together and said it passed just fine on their test bench.

Today's successful running of the engine confirms it all.

They repaired the pump for free but charged me $660 for repainting it....:)

True, I had some lower quotes from online guys (as low as $370) but these guys were local and they do know this CBC pump. They way it turned out, I might have had it shipped back to me in pieces from the online guys when they found the broken solder joint.

It's only money, right? My baby runs again. Yay!
Scott Little
Dale TX

JD 450 w/ backhoe attachment

little1406
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Post by little1406 » Fri May 03, 2013 11:01 pm

Mark, I like your suggestion of removing the entire line but my lines are threaded up from the pump, through the gaps in the exhaust manifold, and onto the injectors. I think I'd have to straighten them out considerably in order to unscrew them from the injectors, no?

Still, as a last resort, I agree that would likely allow me to free the nut from the line, once I had the thing off the engine and on the bench.

Thanks!
Scott Little
Dale TX

JD 450 w/ backhoe attachment

KenP
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Post by KenP » Sat May 04, 2013 4:13 am

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MarkW
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Post by MarkW » Sat May 04, 2013 12:55 pm

Glad you got it back up and running Scott, that is always a relief!

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