Topic: '76 cb550 front brake pipe leak

[Nortstudio]

I noticed a small amount of fluid leaking where the pipe meets the caliper.  The parts list doesn't show a gasket or seal there.  Does this mean I need a new pipe, or is there some other fix? 

Based on what the PO had done to other such issues, maybe I could follow his lead and devise a mixture of bubble gum and duct tape backing glue to hold me over....

Any advise is much appreciated.

Thanks,

Scott

[MoMo]

I assume it is tight.  If so, You may just need to remove the tube and clean the caliper seat and lock nut that is on  the tube. Sometimes the tube has to be bent so that it goes in straight..Larry

[luap]

is it a new tube? if so the flange need to be the same as stock.
if you tighten it all the way an the pipe is still loose I would say the flange is wrong. we just did it on my buddys bike but he is running a single braided cable an needed a special reverse flare bung flange

[Nortstudio]

It's tight.  But the pipe and nut looks pretty rusty.  I'll try cleaning and reseating it.  it appears to be stock, but I have no way of telling.  It didn't used to leak, so I'm not sure what changed.

Thanks for the responses.

[bollingball]

Take it back off and look real close at the threads I hope you did not cross them up compare the length of threads to the old one are they longer? Slide the nut up an clean the flare with steel wool then blow it off good how does it feel on the first 2 or 3 turns it should turn easy.

[Nortstudio]

The only time I have ever had this off was to flush and redo the brake fluid.  I recall it being smooth to put back on, and remember the ease of it wanting to cross thread.  So I am pretty sure I got it on there without doing that.

Tomorrow I will check it and see if I can't clean it up a bit.  It really is leaking only a little, so hopefully a nice clean and reseat will do the trick.

Thanks everyone.  I'll let you know.

[Duanob]

Check the tube for a hairline crack. I had it happen. The more I tightened it the more it leaked until I found the crack on the flange.  I replaced the tube.

[Nortstudio]

Thanks Duanob.  Checking later today.  I'm hoping it's a cleaning and not replacing that this calls for.

[cameron]

Just in case
http://slingshot-cycles.com/index.php?main_page=product_info&cPath=1_58_7&products_id=56

[scottly]

Nort, you are using a proper flare wrench, right? It can be difficult to get enough torque on the flare nut to seal properly with a standard open end wrench without distorting or rounding off the corners of the nut.

[Nortstudio]

I actually didn't.  I don't have any of those special wrenches, just a good box-end wrench.  I was careful though, having see what the PO did to the bleeder (and just about every nut on the bike!).

Should I go grab a set of flare wrenches?  Would we be using them on other parts of the bike?

Thanks for the advice.

[bollingball]

You don't need a flare wrench if you got a box whench on. How did you manage that Is the box wrench just left on the bike

[Nortstudio]

The open end   Although, with some of the things that the PO did to this bike, it would NOT have surprised me in the least.

I'm hesitating with checking it, because I really don't want to get into the brake fluid spilling all over the curb.  I wrench on the street here in Brooklyn, and unfortunately, it causes me to delay some things, when I really should just get to it.  Today is a perfect day for it.  33 degrees and rising, sun is shining on my side of the street....

No excuses!

[stueveone]

How about Teflon plumbers tape? Not sure it would hold up to the brake fluid though?

[Nortstudio]

How about Teflon plumbers tape? Not sure it would hold up to the brake fluid though?

Not a bad idea. Certainly not typical fluid that tape crosses paths with....but can brake fluid be much harsher that Brooklyn water?

[flybox1]

How about Teflon plumbers tape? Not sure it would hold up to the brake fluid though?

no need to mcguyver it.  
+1 on the pipe tape.
2 years and no leakey for me!    saves from having to repaint the caliper.
I just put 2 turns on the lowest 4-5 threads so it sunk in deep when screwd in all the way.
..but yeah...clean it up real well first.  no rust helps.

[TwoTired]

Except...

A flare fitting is supposed to seal at the compression interface of the flare.  The threads are just a wedge to hold the flare in place onto the cone. 

Cheers,

[scottly]

Pic attached of a flare wrench. It's a cross between an open end and a 6 point box end. They are thicker than a standard wrench so as to spread the load out more evenly on the nut. Just buy the size you need, not a whole set.

[Nortstudio]

Thanks Scottly. I looked them up right after that first reponse, and definitely recognize them from Sears, just never knew their purpose. Are there other parts of the bike that require these?  I have a gift certificate burning a hole in my pocket, so....

If I will never need one for anything else, good call on just the one though.

[scottly]

They are designed for flare fittings. No need for a whole set, as far as your bike goes. But, hey, if you have a gift certificate.... I never regret buying good tools; they save you time and money in the long run. The set will cost less per wrench than one at a time, but if you only use the one, the money saved can buy other tools that you can actually use.

[Nortstudio]

I think I'll stick to the one wrench. I can still use so many other tools, I'm best saving the GC for other items.

Thanks.

[scottly]

When you get the wrench, I would back the nut off ever so slightly, then tighten it up a wee bit past the starting point. If it still leaks, more torque may be required.