hoggyf Posted May 9, 2012 Report Share Posted May 9, 2012 Tried bleeding up my back brakes last night with a gurt big syringe and can get nothing moving - pulling or pushing through the bleed nipple, last time a mate of a mate bled it through the banjo on the rear caliper but I can get no movement no matter what i do. Is it time to strip absolutely everything out of it and check for blockages?? Quote Link to comment Share on other sites More sharing options...
neilnh Posted May 9, 2012 Report Share Posted May 9, 2012 Might sound like a silly answer but the brake nipple is loose enough and the filler cap is off Quote Link to comment Share on other sites More sharing options...
hoggyf Posted May 9, 2012 Author Report Share Posted May 9, 2012 Arghhh after the day I've had (nowt to do with trials bike!) yes it is a silly question, but I appreciate the sentiment and yes, bleed nipple is loose and clear of obstructions and cap is off. Love playing on my trials bike and love tinkering with bikes in the garage - hate tinkering with trials bikes - they're too bloody small!! - lol Quote Link to comment Share on other sites More sharing options...
shyted Posted May 9, 2012 Report Share Posted May 9, 2012 Think stripping the assembly should come after you find the problem.Get shut of the problem once and for all and save yourself stress . If the nipple is corroded or damaged get rid and buy a new one and use the dirt cover . When you put it in ,use a tiny smear of copper slip on the threads and don't over tighten it . Before you put it in make sure you get fluid through the recess thus removing crap from down there,but take it easy or brake fluid will be everywhere Quote Link to comment Share on other sites More sharing options...
coxy Posted May 9, 2012 Report Share Posted May 9, 2012 Have you taken off the adjustment on the small pin at the brake pedal completely? The piston in the master cylinder needs to be as low in the cylinder as possible so the fluid can go past when using a syringe. Also try pumping the brake via the pedal and slightly crack the banjo bolt on the master cylinder you will hear a hissing noise when undoing the banjo bolt if there is any air in there. Most air gets stuck in the master cylinder rather than in the pipes etc. Quote Link to comment Share on other sites More sharing options...
tankygsy Posted May 9, 2012 Report Share Posted May 9, 2012 (edited) Should be a piece of cake. Loosen bleed nipple, fill reservoir and pump the pedal. When all the air is out close the nipple, pull brake in, open nipple, close nipple - do this several times and voila! Make sure you can blow through the bleed nipple with your mouth before you start. If not then its likely to be full of dirt, get a pokey tool and clear it. Make sure the reservoir stays full or you will suck air in. Edited May 9, 2012 by tankygsy Quote Link to comment Share on other sites More sharing options...
lee99780 Posted May 9, 2012 Report Share Posted May 9, 2012 Get a pipe off the nipple into a milk bottle with a bit of fluid in, keep pipe below fluid, crack nipple off and pump the brake slowly, keeping the res full, you should see all the air come out and then the level should rise when no more air is in the system Quote Link to comment Share on other sites More sharing options...
jse Posted May 10, 2012 Report Share Posted May 10, 2012 Bleeding the back brake can be a big hassle, as most of us know. One of the big problems is that the "feed" line from the reservoir is below the pressure outlet (which allows a big bubble to stay in the hose fitting area). The other problem is that using pedal pressure does not move enough fluid to dislodge a bubble of any size. The two best ways I've found are: 1. Use a large syringe hooked into the reservoir line to back bleed towards the caliper (making sure the M/C piston is retracted back). 2. If that doesn't work, loosening the M/C, lowering it down and turning it upside down, then pushing on the piston (a #2 Phillips screwdriver works well) and bleeding the system in the "traditional" way. Jon Quote Link to comment Share on other sites More sharing options...
shyted Posted May 10, 2012 Report Share Posted May 10, 2012 Hoggy f ,did you get sorted ? What was the problem ? Just interested thats all . Love working on trials bikes (and bikes, trucks ,etc in general ) . Quote Link to comment Share on other sites More sharing options...
hoggyf Posted May 11, 2012 Author Report Share Posted May 11, 2012 Confession time i've had problems bleeding the brakes before so assumed that was the issue but on further inspection the other night nothing was coming through the hose to the caliper, thats when I realised something wasn't right, and the problem had got worse after re-fitting the engine. Soooooo..... the hose from the master cylinder was trapped between the engine and swingarm crimping it closed, unbolted the swingarm amd moved it to the side then tried bleeding it with the syringe and it bled up no bother. So the moral of the story is have a bloody good look first and don't assume anything!! Feel a right dick now!!! but its back up and running so never mind. Cheers guys Quote Link to comment Share on other sites More sharing options...
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