Triumphrat

oldretrorider

As my last winter project, I installed BellaCorse Highlander handlebars, following the Haynes manual to replace the throttle, clutch, and brake lines. I was real proud of myself until it came time to bleed the brakes. No matter what I do, I can't get any pressure on the brake handle. I got lots of bubbles, and then it looks clear for a while, but still no pressure. Then I tried turning the handle bars the other way, and got more bubbles, and then clear, but no pressure. Could I have a leak somewhere? Or do I have to keep bleeding it to get air out of the nooks and crannies of the lines? I'm totally puzzled.

davidc

Use the search, OldRetro, specifically in twin tech talk; you'll get many hits to help you with this apparently common problem. Just read something about a crush washer that ought to be replaced or else air leaks - stuff like that. You'll definitely find the answer!

propforward

Yes, I have read that sometimes an airlock forms. If memory serves there are 2 common solutions

1. Crack the banjo bolt on the master cylinder open a bit, to let the air out, then tighten up and continue bleeding.

2. Pull the front brake lever in, tape it and leave it over night, then continue bleeding.

As I recall people have had success with both methods.

Be careful not to get brake fluid on anything of course.

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Rule 1: Cardio

Rustic Road Progress

Pokeyjoe

I replaced the pee cup on my Scrambler with one of those little black jobs. I had a rough time bleeding the brakes as well. I gave up and went back to it the next day - it was fine. PFM.

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John
3-7-77
Some people are like Slinkies. They're really good for nothing. But they still bring a smile to your face when you push them down a flight of stairs.

oldretrorider

I had no idea that bleeding brakes on motorcycles was such a problem. I was worried for a while there that I had done something horribly wrong when replacing the brake line.

I'm trying the rubber band thing first, if only to give myself a rest until tomorrow. I also might try one of those pump things.

Pokeyjoe

I used a vacuum bleeder. The only thing that helped was turning the handle bars from side to side to release some air (bike on side stand).

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John
3-7-77
Some people are like Slinkies. They're really good for nothing. But they still bring a smile to your face when you push them down a flight of stairs.

Baltobonneville

I'll be doing the front brake line this spring, bought a replacement banjo bolt that has a bleeder in it for the top end of the new brake line. I'm going to try it, take some pictures, and bleed it at both ends with the Mity-Vac. If it works out, I'll post some pictures.

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Marty
2005 Bonneville Blue 790cc, AI removed, Staintunes RC, Unifilter, no snorkel, 118/40/Thrux needle/1 shim/3 turns, tachometer, Ikon 7610s in back, Ricor Intiminators in front, Pirelli Sport Demons, D9 gauge panel.

oldretrorider

The rubber band trick didn't work, so I bought a vacuum bleeder and what do you know -- it worked. The brakes are nice and firm now. Used about a pint of DOT4 before I got all the air bubbles out.

So I took it for a test ride, and nothing fell off, but now I've got a new problem. On wide-open throttle I get stuttering and power loss. There is nothing wrong with the idle, and it runs fine at a steady speed, but when I go for a blast of acceleration, I immediately get what feels like misfiring and popping before it finally starts accelerating.

Any thoughts on what it could be? I checked the clamps on the rubber boots between the carbs and the engine, but they were as tight as they could be. Could it be dirt that somehow got stuck in the needles when I removed the carbs to get at the throttle linkage?