|
|
Post by stevie16v on Jan 13, 2011 17:51:01 GMT
As you all know im currently rebuilding/refurbing a 93 xj600. I balanced the carbs today and it sounds awesome! (although its a pain to get into the sync screws)
Made my way to the front and tried flushing the old brake fluid through, pressing the lever it came all the way to the grip. adjusted it, still the same. undone the hose etc when i press the handle very little (eg a drip) came out i cleaned the reservoir as it was disgusting. If i hold my finger over the outlet valve i can feel pressure building up, I let my finger off and a small spurt of fluid comes out (thinking thats ok) all back together. try bleeding it. nope it wont push anything through the bleed nipple. im assuming the master cylinder has maybe gone and isnt proving enough pressure, would that be right?
|
|
|
|
Post by Flymo on Jan 13, 2011 17:57:58 GMT
I once spent ages trying to bleed my rear caliper and couldn't at first work out why i wasn;t getting any fluid from the bleed nipple... untill i unscrewed it completely and then plenty of fluid came out of the hole in the caliper... Reason... Bleed nipple clogged up with crap, took a sewing needle to the bleed nipple and was soon sorted.
it's a long shot but maybe worth checking.
the other thing i do now if i've stripped the caliper completly and know it's full of air is attact a longish piece of clear (must be clear) tube to the bleed nipple and suck on it till i can see fluid in the tube, then resume normal bleeding routine.
HTH Flymo
|
|
|
|
Post by stevie16v on Jan 13, 2011 18:18:14 GMT
bleed nipple checked. Fluid does trickle out of it. When applying the brake, the pistons dont move, no brake pressure at all and there isn't a feeling to the lever.
As for the clear tube, im so stupid that i'd end up with a mouth full of brake fluid lol
|
|
|
|
Post by Flymo on Jan 13, 2011 18:38:24 GMT
i'd perservere a bit then, or you can tape back the lever touching the grip and tap the pipework to loosen any stubborn air leave it for an hour or so and then try bledding it again, sometimes works.
|
|
|
|
Post by pilgrim on Jan 13, 2011 18:56:49 GMT
I've had problems with back and front bleeding and decided to go back to basics. One of the essential things is to give the air time to rise to the top and operate the lever/pedal s l o w l y. If you keep trying to pump the fluid through you're probably maintaining the air in the same position. Keeping the lever held in overnight works too! (use a rubber band, don't sit on the bike all night though..........  ) ;D |
|
|
|
Post by stevie16v on Jan 13, 2011 19:14:06 GMT
should i leave the bleed nipple open overnight aswell?
|
|
|
|
Post by m40man on Jan 13, 2011 19:32:00 GMT
should i leave the bleed nipple open overnight aswell? No. |
|
|
|
Post by bobh on Jan 13, 2011 21:09:49 GMT
The alternative is to use a syringe full of fluid attached to the bleed nipple to pump fluid (and air bubbles) back up the pipe into the master cylinder.
Also, try loosening the banjo on the master cylinder and pump (with a rag round it) until clear fluid comes out.
It's a messy old business. Count yourself luck you've only got one caliper to worry about!
|
|
|
|
Post by amorti on Jan 14, 2011 9:09:51 GMT
You probably have a failed master cylinder seal. The insides of a master cylinder look a bit like this:  If the first seal fails, you won't get any pressure in the brakes, but it won't actually leak until the sweeper seal fails too (which it will do). That doesn't get past the transfer port, so all it does is pump fluid between the bore and the reservoir, IYSWIM. Solution is to open it up and have a look - just remove the circlip and it'll all come out easily. If it has failed (ie, any visible nick or degradation of the rubber at all), then you need to decide whether to fit a rebuild kit, or to fit a far superior Honda 1/2" front master, eg. from a Blackbird or VFR with linked brakes (check with seller that it's 1/2"). Goes straight on, you just have to re-wire the brake light switch with some ordinary female spade terminals. Makes an incredible difference to braking performance, you won't believe it's the same brakes at all. s74.photobucket.com/albums/i264/a_morti/divvy%20master/diversionclub.proboards.com/index.cgi?board=600&action=display&thread=7510&page=1 |
|
|
|
Post by General Gman on Jan 14, 2011 10:00:28 GMT
TBH, before you start refurbing the master cylinder, it's worth bleeding at the master cylinder first.
Bleed as you would at the caliper, but instead of using a bleed nipple, use the banjo bolt as a bleed point.
This technique is essential on my bike to get any pressure at all before bleeding from the calipers.
Make sure you cover everything locally to make sure that you don't brake fluid on any surfaces
Certainly worth a try before you get stuck into actually having to spend money.
|
|
|
|
Post by stevie16v on Jan 14, 2011 16:42:27 GMT
Thanks for the replies folks. I've tried everything suggested apart from stripping the master cylinder. But i think i can pretty safely say thats what it is. Thankfully no rush to get it on the road so ill get around to replacing it at some point soon  |
|
|
|
Post by amorti on Jan 14, 2011 22:33:42 GMT
Thanks for the replies folks. I've tried everything suggested apart from stripping the master cylinder. But i think i can pretty safely say thats what it is. Thankfully no rush to get it on the road so ill get around to replacing it at some point soon Get the 1/2" honda master cylinder, YKIMS  Or, if you haven't ridden the bike yet, you don't. But trust me (and Ringwood's Old Thumper) it does. |
|
|
|
Post by stevie16v on Jan 15, 2011 19:47:54 GMT
So would i be able to just swap everything over without hassle? eg lever, mirror etc? obviously with the minor mod for the brake light switch
|
|
|
|
Post by amorti on Jan 17, 2011 9:50:37 GMT
So would i be able to just swap everything over without hassle? eg lever, mirror etc? obviously with the minor mod for the brake light switch Yes just swap over the two parts wholesale, it's as easy as that. All bars are 22mm (harleys and moto-x excluded), all banjo bolts are M10x1 (brembo excluded) and in this case you are lucky as the lever clears the switchgear. You use the original yamaha clamp-mounted mirror carrier as the m/c mounted one crashes your screen. You may have to enlarge (ovalise) the holes in the mirror clamp, so just ream with a 6mm drill bit. Or you may not, and that might have been when I put a Brembo master cylinder on my old Honda. |
|
|
|
Post by stevie16v on Jan 17, 2011 17:29:29 GMT
|
|
|
|
Post by amorti on Jan 17, 2011 22:24:29 GMT
Yes, just need the lever and to change the connectors on your brake switch, then you're off. Description says clutch but it's clearly a brake master in the picture. |
|
|
|
Post by stevie16v on Jan 26, 2011 21:48:27 GMT
bloody back brake is the same now aswell. pedal travels all the way, no resistance and the pistions aint moving. ffs, just not my luck
|
|
|
|
Post by amorti on Jan 27, 2011 9:00:08 GMT
bloomin back brake is the same now aswell. pedal travels all the way, no resistance and the pistions aint moving. ffs, just not my luck And in tomorrow's lesson, we deal with "preventative maintenance", or "the art of fixing stuff before it breaks". |
|
|
|
Post by stevie16v on Jan 27, 2011 10:17:55 GMT
Lol Aye ok smart arse. Believe it or not, this is me trying to square it up before it goes back on the road. Turning out more hassle than its worth......Anyone fancy an xj 600 project? not much left to do, I've just lost the will to live with it
|
|
|
|
Post by General Gman on Jan 27, 2011 11:51:28 GMT
So would i be able to just swap everything over without hassle? eg lever, mirror etc? obviously with the minor mod for the brake light switch Ye all banjo bolts are M10x1 (brembo excluded) and in this case you are lucky as the lever clears the switchgear. I thought almost all Jap braking systems used M10 x 1.25 (metric fine) apart from Suzuki who like to be different and use M10 x 1.0 Certainly, the only ones I've ever seen that were M10 x 1.0 have been on Suzukis |
|
|
|
Post by stevie16v on Jan 30, 2011 15:24:24 GMT
Turned out not to be the master cylinder, it was the hose, must have been an internal fracture in i as it wasnt losing fluid but was pulsing when bleeding it and not holding pressure. New m/c, hose and caliper on. Jobs a good un .............Now onto the carbs and back brakes.... |
|
|
|
Post by amorti on Jan 31, 2011 8:42:06 GMT
Turned out not to be the master cylinder, it was the hose, must have been an internal fracture in i as it wasnt losing fluid but was pulsing when bleeding it and not holding pressure. New m/c, hose and caliper on. Jobs a good un .............Now onto the carbs and back brakes.... My post above was meant to have a " " on it, sorry if it came across harsh. Keep going, you seem to be so far in now, that you must prevail. |
|
|
|
Post by stevie16v on Jan 31, 2011 8:49:19 GMT
Don't be daft amorti. I can take a fair joke. Had a wee laugh at it. Takes a fair amount to offend me Cheers for the comment of hope.....Todays lesson, How to resolve a bike which is revving its head off from start |
|
)
