G oog le BadWeB | Login/out | Topics | Search | Custodians | Register | Edit Profile

Author Message   Fasted Posted on Monday, March 27, 2006 - 10:34 pm:        bought a bike with rear disc removed. owner swears brake will work if reassembled. i reassembled and am having trouble generating any pressure. if i inject fluid into bleeder under pressure, it fills rEservoir. however, i can't build any pressure to bleed. loosening banjo bolt passes mostly air when pedal is pressed . MASTER CYLINDER?   Blake Posted on Tuesday, March 28, 2006 - 10:12 am:        It can take a lot of lever pumping to get the pads to engage the disc prior to there being any significant pressure build-up. Other than that, it would seem likely that the master cylinder may need some cleaning. If the plunger/piston gets gummed up, it won't return and will behave as you describe.   Blake Posted on Tuesday, March 28, 2006 - 10:15 am:        The master cylinder could have become gummed up due to old fluid, moisture, or mixed DOT 4 and DOT 5 fluids. In most cases, you should be able to disassemble, clean it and have it working again.   Road_thing Posted on Tuesday, March 28, 2006 - 10:51 am:        Everything Blake said. If I were doing it, I'd strip the master cylinder and the caliper and clean them thoroughly with mineral spirits. Flush the line, too. Blow everything dry, then reassemble, filling with clean, fresh brake fluid as you go. Make extra sure that the sealing washers on the banjo bolts are really sealing. It's easy to have a tiny leak there that will make it absolutely impossible to bleed the system until the pedal is firm. It's a pain in the butt, but eventually you'll get it. rt   Blake Posted on Tuesday, March 28, 2006 - 05:25 pm:        I second cleaning the entire system. And yeah, until you can get your lever to firm up, you just won't be satisfied.   Jayvee Posted on Friday, March 31, 2006 - 02:16 pm:        I want to know about the disc, I'm wanting to replace my disc, for example to a Wave or something. Just for looks, what I have works fine. Do I really need to pull the bearings, as the manual say? Can I just pull the wheel, and unbolt the disc and bolt the new one back one? I know it's red-loctited, I was thinking of applying the micro-torch to each bolt, to break the red stuff loose.   Captainkirk Posted on Friday, March 31, 2006 - 10:03 pm:        Nix on the micro-torch. A heat gun works just as well with less collateral damage.

Add Your Message Here Post: -Color- Black Red Green Blue Yellow Purple Orange Cyan Gray White -Font- Arial Courier Symbol Times Verdana -Size- Smallest (-2) Small (-1) Normal Large (+1) Largest (+2) Username: Posting Information: This is a private posting area. Only registered users and custodians may post messages here. Password: Options: Post as "Anonymous" (Valid reason required. Abusers will be exposed. If unsure, ask.) Enable HTML code in message Automatically activate URLs in message Action: