jethin

I inherited a rusty, crusty French frame with internal cable routing. The brake housing was frozen inside the top tube. With great difficulty I managed to pull out the wound steel wire and inner liner, but the outer plastic liner (and possibly other gunk) is stuck inside (the walls of) the internal cable sleeve in the frame.

I figure I'll seal up the holes and use top tube clamps, but I'm curious if anyone has any ideas about how I might be able to clean out the inner cable sleeve. I tried to jam a good brake housing in there and it wouldn't budge. Chemical solutions are off the table for me.

bboy314

I have an old GT MTB frame with a similar issue. Haven’t really tried much yet, but I am considering pouring boiling water into the holes to see if that softens up the housing. Maybe followed by compressed air to dry it out, and some oil or frame saver. I’m curious to see what advice others chime in with.

Classtime 

Heat. If it doesn’t mess with the paint. I’ve used a heat gun to remove various stickers and got the frame tubes mighty hot with no ill effects to the paint. Maybe the internal sleeve is close to the wall of the top tube?

oneclick 

What's likely happened is that the inner surface of the tube has rusted; rust being bigger than iron it has forced its way into the sheath all along the length, locking it in place.

Try a strong solution of oxalic acid poured down the tube - plug one end and give it a day.

(Or dip the whole bloddy thing, sounds like you might as well.)

randyjawa 

So, if I understand this, the outer cover of the cable casing is stuck inside the frame cable tube? If that is the case, get a coat hanger, the old metal kind, and cut off a foot or so. Using a hammer and an anvil (another hammer will work), flatten one end of the coat hanger piece. Flatten and then test to see if it enters the hole. If so, flatten a bit more, until it just fits. Now, gently push the fabricated tool into the hole, twisting back and forth while doing so. Now, try inserting a transmission cable, carefully. If it does not go, repeat the insertion/twist program, and try again.

Anyway, that's the sort of thing I would try.

unworthy1

or maybe a gunsmith-y wirebrush (such as you might use to clean out a small-bore firearm) on a stiff but flexible rod of your own devising.

Bad Lag

Don't use heat, use the absence of heat (cold) - freeze spray. Get it super cold.

Plastics shrink hugely when they are cold. They also get stiffer. Silicone oils do not freeze when cold - spray some in the tube to minimize friction..

You can try pushing it out but most long, thin push rods will bend when you try to push them in.

You can also try pulling it out. Feed string or solid steel wire through the hole. Attach an appropriate sized fitting to the end, then, pull it back through.

droppedandlost 

I don't know about the entry angle, but maybe a long thin screw, might grab the housing so you could pull it out

Jeff Neese

Would the end of a shifter cable fit through the tube, maybe with a little grinding or filing? If so you could feed a shifter cable through until it catches on the end of the housing, and pull.

rccardr 

I‘d be tempted to try to push it out rather than pull it out. Get the entire top tube as cold as possible to stiffen the housing, then push from ether end using a piece of stiff wire hanger inserted until it can’t go any further. All you need is anninch or so of housing to emerge, then you can pull/twist the rest out.

merziac

I would sharpen a spoke and carefully try to force it between the casing and the rusty wall at both ends to start an ingress, then dribble some penetrant in, wait and repeat the probing.

Bad Lag

Steel shrinks very little. Plastics shrink a LOT.

Bad Lag

The "pull through" technique is equivalent to a push, in terms of mechanics - the fitting pushes on the housing. It is just that the force is applied to the fitting by a pull.

Bad Lag

Let me go one further, which is probably overkill, ream it out.

Even a braided steel cable (brake cable) can be spun by a drill motor. If the little fitting has cutting edges on it, it will obliterate the plastic housing as you pull it through.

miamijim

Slide a new inner wire through… then push each end and alternates ends until it breaks loose. A lot times the outer plastic is tore and is catching on the inside.

once it’s lose slide it out over the wire.

bark_eater 

Technically Goo-Gone is a chemical, but if the issue is stick degraded plastic, I'd at least test it.

jethin

Thanks for all the ideas, C&V cognoscenti! I’ll plan to try a couple of ‘em out soon. In the meantime keep them coming.

zukahn1 

Yes the thin spoke with a bit of waiting none forcing effort does seem to work

Bad Lag

Oh, I've got it! Melt it out. Oh,... no,.... wait a minute, don't do that.

If you get it hot enough, it will expand but lose all its strength. You should be able to do a pull through.

Classtime 

I still think heat to soften the plastic. Cinch the end of a brake cable nipple into a drill chuck and feed the cable into the tube and spin that drill. I predict the cable flapping around in there will chew up the softened housing cover. Maybe even fray part of the cable. After a bunch of this, file that; cable end to just fitting in the tube and feet the cable through and putl out the chewed up plastic.

Alternative: "make" a ferrule fit in each end of the tube to act as cable stops.

Steel Charlie

Jethin

Please tell us if any of the suggestions works ! I may have one like that coming to visit would welcome having some possible approach

TIA
Charlie

PhilFo 

Cut the plastic cover off of a long piece of spiral wound brake housing, make a ragged cut on one end, stick the other end in a drill chuck and use that at low speed like a plumber’s snake. Bad Lag mentioned something like this a few posts up. Make sure to spin your drill in the direction that your housing snake spiral will tighten, as if it snags and expands rapidly inside the tube it’s all for naught. Good luck and keep us posted!

Keefusb

I would spray some PBlaster down into the tube and let it sit overnight. Then use a copper twist brush like you would use for cleaning a small bore shotgun or long gun/rifle barrel and try to twist and push all the gunk out of the tube. I would be wary of using a heat gun or similar if you care about the paint.

I had an internal cable tube like the one described by the OP on an old Raleigh and that's what I used.

The brushes can be had for $15 or $20, and may come in handy for other cleaning tasks.