Brake line banjo fittings won't seal

[bwringer]

I just had a set of stainless braided brake lines made down at the local motorcycle shoppe. I went from the standard three-line setup to two lines. Both lines are attached to the master cylinder with a double banjo bolt.

I can't get this connection to seal!

I've tried aluminum and copper crush washers and two different banjo bolts. It always leaks on one side or another of the same banjo fitting, so I swapped ends on the brake line. And whaddya know, that one leaked in exactly the same way. The leak is always between the banjo fitting and the washer, and it starts dripping before I even move the brake lever

The connections on the calipers seem to be OK (no dripping, anyway), but I haven't had any pressure in the system yet.

I also tried placing the leaky fitting in both positions, next to the master cylinder and next to the bolt head. Same results.

And yes, I did have new washers in the correct positions each time:

master cylinder:washer:banjo:washer:banjo:washer:bolt head

Like this:

=|o|o|#

I've got brake fluid and a small fortune in washers all over the garage. Fortunately, the auto parts store has 10mm crush washers for 39 cents each instead of the $1.99 the bike shop wants.

The banjo fittings appear to be even and undamaged. They measure exactly the same thickness and diameter all the way around, so I don't think they were damaged during assembly.

So far, damaged banjo fittings are my best theory, but I find it hard to believe both fittings on the same hose are bad and I can't find any evidence that they are damaged or misshapen. Anything's possible, though.

Any ideas?

[Anonymous]

hose

one of the banjo fittings has a defect in the surface position, may not be square with the other side, take a vener caliper and check it out, you can reuse the copper washers if you aneal then first

[Anonymous]

I also had this problem after switching to braided lines. What happened was that after I had the brakes bled I took both hands and gave the new brakes a good squeeze. End result, blown master cylinder piston. The fluid was actually dripping out of a drain hole in the bottom of the master and finding it's way around the washers. It took me a month to figure it out. :x

Steve

[Jethro]

Yeah, I also got Paragon lines for my bike, I had a leak that was a couple of drops a night, I could have sworn it was the rebuild of my anti-dives, but it was the crimp on the banjo fitting. Sent it back, sure enough- bad crimp. I had rebuilt the anti-dive 3 times and used all new crush washers too. Bad crimp. Paragon took care of me.

Brake fluid travels in weird ways.

[bwringer]

Under a strong light and magnification, I finally found the surface defects on the sealing surface of the fittings.

It's not readily visible, but about half of the sealing area on the affected fittings is very slightly crushed -- exactly like some fumble-fingered mouth-breathing idiot bike shop mechanic squashed the fittings with a pair of pliers or in a vise. Aaaargh.

Both fittings on one of the hoses are damaged. The fittings on the other hose seem OK. I'll test it by hooking up just one caliper and seeing if that leaks.

This is rather inconvenient -- the bike shop is about 25 minutes away from my office through heavy traffic. Hopefully they'll replace the fittings without giving me too much crap.

I thought about sanding or filing the fittings, but it would be rather difficult to get an absolutely flat surface, and would keep me from returning them.

I do have to say I'm a little disappointed with the quality of the workmanship and the parts used. The fittings are ordinary plated steel, not stainless, and the walls and sealing surfaces of the banjo fittings are noticeably thinner than those on the OEM brake lines.

I was also surprised to see that they built the lines using ordinary screw on fittings. I could have done that in my garage! I don't know why it took them three days, either.

To be fair, I didn't ask first -- I just assumed it was like buying any other custom hydraulic line and they would build them with a crimping machine. My Dad always told me what they say about ASS-U-ME...

I probably can't return the brake lines at this point, but if I can, I'll order a custom length (to fit lower than stock handlebars) set of brake lines from Paragon or Spiegler.

Good thing the weather's going to be nasty for the next week or so. If it was warm outside and I couldn't ride, this mess would probably give me an aneurysm. :twisted:

[Jethro]

I hate to say it....

...should have bought Paragon! Those lines are worth it man, mine are sweet. Go back and tell the manager of the store that these are for an extremely high performance morotcycle and that they have taken your life in your hands and they failed. You can't have to worry about a brake line fitting failing when you are entering a turn at 100mph. They should give you your money back.