Vincent Moy Posted June 9, 2009 Share Posted June 9, 2009 So my 82 XS400 Maxim seems to need more Tender Loving Care than what I have expected. The front brake is really bad. I need to squeeze the lever all the way to get minimal braking. I squeeze the lever to see if there is anything move at the caliper and nothing seems to move. One of the master cylinder cover screw is SO stuck I don't even know how to get it off. Therefore I'm think about replacing the whole front brake system. I want to know which master cylinder as well as caliper will fit my bike. Thanks! Link to comment Share on other sites More sharing options...
Moderator drewpy Posted June 9, 2009 Moderator Share Posted June 9, 2009 you can use a 550 front end with twin disks and master cylinder. if you don't want to go that route, then a magura will do Link to comment Share on other sites More sharing options...
wild foamy Posted June 9, 2009 Share Posted June 9, 2009 chances are the seals need replacing in your brake master cylinder which is common for older bikes. you can replace them or find a second hand master cylinder instead, or do what drewpy said Link to comment Share on other sites More sharing options...
Cy Welch Posted June 10, 2009 Share Posted June 10, 2009 You can also get an aftermarket master cylinder that will work with your bike from MikesXS, just don't tell him its not for an XS650 or he won't sell it to you. Link to comment Share on other sites More sharing options...
Vincent Moy Posted June 10, 2009 Author Share Posted June 10, 2009 You can also get an aftermarket master cylinder that will work with your bike from MikesXS, just don't tell him its not for an XS650 or he won't sell it to you. That's what I'm looking at. I am also wondering if it would be the caliper's problem. One thing for sure is there is no leak and stuff. And I can see fluid in the reservoir. Just whenever I press the lever there seems to be no pressure at all. Link to comment Share on other sites More sharing options...
Cy Welch Posted June 10, 2009 Share Posted June 10, 2009 That's what I'm looking at. I am also wondering if it would be the caliper's problem. One thing for sure is there is no leak and stuff. And I can see fluid in the reservoir. Just whenever I press the lever there seems to be no pressure at all. Could be the master cylinder or the brake cylinder. You need to start by getting the cap off, if only one screw is stuck, just carefully drill the head off, then when you lift the cap off you can use a vise grip to get the screw out and go down to the hardware store and get a new one (may as well replace them all while your at it). Then bleed the brakes first, and see how they work, if they still don't work, you may need to find rebuild kits for them (georgefix on ebay would be likely to have the kits you need, either than or partsnmore.com) and rebuild both. If the brakes have not been bled in a long time there may be lots of crud built up in there keeping it from working, but the first order of business is to get flesh clean fluid in there, as it attacts water and does work as well as it ages. Link to comment Share on other sites More sharing options...
mdsims Posted June 10, 2009 Share Posted June 10, 2009 You can also get an aftermarket master cylinder that will work with your bike from MikesXS, just don't tell him its not for an XS650 or he won't sell it to you. Is this true? Something you witnessed firsthand? I haven't purchased anything directly from Mikesxs.com but I have had a decent amount of contact with Michael "Mercury" Morse over at 650central.com and that guy is pretty awesome. He's a fountain of information and more than willing to help with any of my issues. He answered all my questions until I was satisfied and knew full well I was riding an xs 400. Best part is, he's only 100 miles away. Back on topic - This is what I just did for my front brake troubles: 11mm XS Performance master cylinder (~12.1:1 ratio), slimline and lightweight Vesrah sintered pads Caliper rebuild kit New caliper piston braided stainless line Eventually I may get a nice new drilled stainless rotor, but for now this should make a world of difference for the bike. Turns out the rear disk on a 650 is the same as the front on the 400. Maybe once I strip the bike down and start chopping into the frame, rebuilding the front end and powder coating the wheels, well...maybe then I'll buy that shiny new front disc. Either that or graft a modern superbike setup onto the right side and make a custom mount for a 4 piston caliper. Endless possibilities really. Link to comment Share on other sites More sharing options...
dtmf Posted June 10, 2009 Share Posted June 10, 2009 You can also get an aftermarket master cylinder that will work with your bike from MikesXS, just don't tell him its not for an XS650 or he won't sell it to you. i used the magura front master cylinder - 16mm from mike'XS for my 82 xs400 seca and it work's better than the old leaky stock one Link to comment Share on other sites More sharing options...
Vincent Moy Posted June 10, 2009 Author Share Posted June 10, 2009 I just ordered the 13mm from mikesxs. On other note, should I be able to press the lever all the way to the grip? Link to comment Share on other sites More sharing options...
Vincent Moy Posted June 16, 2009 Author Share Posted June 16, 2009 I installed the new MC, everything seems to be working now!! Link to comment Share on other sites More sharing options...
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