Decided to Junk my XJ1100

[va_blue_stang]

You need to lightly hone the bore. I always check for free movement before doing final reassembly on any master cylinder because I've ran into this more times than not. Honing isn't a big deal; pick up some fine sandpaper (600-800 grit), roll it tightly to form it, then tape it to a wood pencil at one end so it can 'flap'. Chuck the pencil in a drill, and with a bit of brake fluid for 'cutting oil', spin this in the bore. Take the seals off the plunger, and when that will go in and out with no issues, clean it up and reassemble.

The slightest bit of corrosion in the bore is all it takes; many times you can't see it.

Thanks for the honing tip it seemed to help some. I think I may of have the bottom gasket on upside down on the plunger. Should the flared end be sticking up toward the top of the m/c turned downward facing the bottom of the m/c?

[natemoen]

You can also get straight stone brake cylinder hones for under $10 too.

[va_blue_stang]

You can also get straight stone brake cylinder hones for under $10 too.

Thanks for the help, I honed it out but it still acts like the plunger is getting air locked, only way it release itself is if I pump fluid in from the bleeder screw then it pops down. I left it on the bench full of fluid and the plunger pushed in and clamped. The caliper is on the next shelf below it with the bleeder screw open, I'm hoping it will gravity bleed itself tonight.

[natemoen]

Did you check to make sure your lines were clean and clear?

[va_blue_stang]

Did you check to make sure your lines were clean and clear?

Yes I've cleaned and blew everything out with the air compressor.

[crazy steve]

If the plunger still isn't moving freely or sticking anywhere, it's one of two things; either the bore still has some corrosion in it and needs more honing, or the 'splooge hole' is plugged. Yep, there's one on the rear master too. Look here: http://www.xs11.com/forum/showthread.php?t=14

The flares on the seals should both be facing the same way; insert them 'open side' first.

[petejw]

jat,
my 81 sports came with the same size
m/c as the xj's it runs only the front brakes (both callipers)
and works really well, so u could still use
the same master cylinder and u would only need a
double banjo bolt and another brake hose for
the extra front calliper and then hook the rear
seperately.

have u bled the m/c first before trying to bleed
the callipers?

[GARTHXS]

Do you have a mighty vac ?

[jjz28]

I was thinking the spooge hole too. I was making my rear brake stick. Also, so sorry i didnt get back to you until now, i use one on those syringes used to mix 2 cycle gas. I says mixmizer on it and its for mixing differet ratios. Dont give up on the bike. Even if you put double what its worth, it will reward you with the power and ride. Also, if you part it out, you will always think "what if i got that thing on the road". Just my 2 cents but i would definately not let brakes keep me from finishing it.

[va_blue_stang]

I've cleaned the spooge hole first thing when the problem was noticed, but I'm going to take it apart one more time today and see what happens.
It will not come back down without fluid in it either, if I had forgot to mention that.
Thanks everyone for all the help.

[crazy steve]

..It will not come back down without fluid in it either, if I had forgot to mention that..

It needs to be honed a bit more. If there's the slightest bit of resistance in the plunger going in and out of the bore, that's enough to cause your problem. Also clean the plunger with some fine steel wool (0000 grade), that will help.

[va_blue_stang]

Went out and check it this morning after it settled over night and think I found my problem. I believe it still has crud in the system. The m/c has stuff in the fluid and the plunger wouldn't release itself. I drained the m/c took the plunger out, sprayed it and the bore with cleaner and reassembled. With no fluid it pushed back out easily on its own. Put fluid in and stuck again.
I made sure the spooge hole was cleaned out also, only thing I can point my finger at now is crud is still in the system.
Also popped the piston out of the caliper and it had crud back in it also.So hopefully a lot more meticulous cleaning will help. I'm going to finish stripping the ate up paint off the caliper so it will not find it's way back in during reassembly.
Thanks everybody for the help this has been the most aggravating project I've ever took on with this bike.

[jjz28]

Just stick with it man, like i said, at least you will be rewarded in the end and the bike will not defeat you. I just dont want you to miss out and part out the bike when they are so fun. If there is any crud in there i would say it will find its way to the spooge hole everytime until you get it ALL out.

[crazy steve]

Went out and check it this morning after it settled over night and think I found my problem. I believe it still has crud in the system..

Make sure you remove the plastic reservoir and clean under that; you'll be amazed at the amount of crud you find under those, and that will continually seep out and contaminate the rest of the system. The last one I disassembled, I got nearly a teaspoons worth of corrosion out of there...

[va_blue_stang]

Whats the best way to clean the brake line?