I have never been a mechanic. The bikes I did work on were all dinky dirt bikes, 25 years ago. The XJ is a different animal. I've only had my 81 750 RH a couple months.

I replaced my tires of dubious age, sidelining the bike for three weeks while I ordered tires, attempted my own dismount/mount, then gave up and paid to have them done. Back wheel, which I thought would be the complex one, was easy, although after having cleaned the drum and backplate area of dust, regreased all applicable areas and replaced the back wheel, I seem to have no pedal. Not sure if I simply need a new spring (don't seem to) or if I've mis-adjusted somewhere. Not my biggest problem...

Just went around the block, and found the front brakes rubbing. I could tell I didn't have good play in the front wheel, but hoped it just needed to "loosen up". No such luck. The wheel was such a bitch to get off and on, as it required removing the fender ("mudgard" in the manual) and twisting the forks to free the discs from the calipers. Putting it back on took me about 1/2 hour to get it all lined up right, making sure that the pads stayed separate and the forks didn't twist out of line as I put the axle ("spindle") back through.

So, I was wondering, before I took it all apart, does anyone see where I went wrong? Is there something I should/can do to relieve the rubbing? The brakes do work, in that there is more pressure to put on the disc when applying the lever, but this can't be good... obviously.

I'm jonesing to ride, but have been playing it safe. Help!

JC

Seriously?? 19 views so far and no one has any ideas??

I guess I take it all apart again and put it back together, and hope whatever I did wrong I do right this time. Not anxious to do that...

I don't expect the magic answer, but has anyone encountered this before or have any ideas? No liability implied by giving your best guess.

:) We're all here - but I find myself a bit lost... I need a hint of the source of the problem and from your description I'm not sure I can help much.

I wonder if the brake lever got squeezed while the bike was apart? The piston might not be travelling freely and got stuck a bit out. If that's the problem and the rub isn't too pronounced you can ride it out... of course this will waste some brake pad and won't solve the real problem. If this is the problem you just need to take the caliper apart clean and put fresh seals in. I know it isn't a hard task but I'd take it to the stealership personally as it won't cost all that much and it would give me the peace of mind.

I like do it yourself - but - when it comes to brakes I do cars and keep it simple. Pads fine - bleeding fine - taking apart the caliper hasn't thrilled me. Perhaps with someone competent standing behind me I'd feel differently.

Otherwise - I'm not sure. Normally this kind of problem is encountered when new pads are installed ( because the new pads are thicker).

Thanks, Woot, for the reply. Liked the "we're all here" part...

Not sure what to add in elaboration of the problem. I'm guessing somehow the calipers got extended beyond their operational range while the wheel was off, but can't imagine how. I'm certain no one used the lever, and even so, I had wooden shims in between the calipers to prevent any squeeze from ejecting them.

I realize I'll at least have to dismantle and re-assemble, if only for peace of mind, before giving in to a professional. Like you, I'd rather leave some important safety areas to them. I just thought the wheel removal would be easier and wouldn't get me involved with the brakes.

So, might it be safe to say you haven't had this problem, and that the wheel has gone back on and inside the calipers smoothly? If so, that tells me I'm off base somewhere, then it's just figuring out where.

It all started when I violated one of my cardinal rules: "Leave bad enough alone".
Didn't really need a front tire to begin with, was just being sure.

JC

If this wasn't happening before you took the wheel out, maybe there is a spacer missing / incorrectly installed on the front axle?? This would possibly make the forks pull together at the bottom / flare out which would mis-align the calipers and explain the rubbing. Best to check a manual with the exploded view of parts to check they are all there and in the right order.

Also when you said the front wheel was a bitch to get off and "twisting the forks to free the discs from the calipers" sounds like the calipers might be seizing as Woot suggested. Try removing the caliper bolts and try to slide the caliper around the disc. If the caliper is seized or binding it will be stuck to the disc and you wont be able to move it. Rebuilding calipers is technically not hard, but it is messy and probably best left to a shop. Good luck!

Oh you get to buy a new tool! One of my favorites too! You need a caliper spreader. They are cheap , about $10 US. Remove your front wheel, brake calipers and the brake pads. Place the spreader into the caliper and compress the piston back into the caliper. If you have one, a medium sized c-clamp will do the job. Just use a rag on the outside of the caliper to keep from scarring it. You just screw the clamp pushing the piston back into the caliper. The spreader works the same way except it has a plate to hold it against the other end of the caliper.
Replace the pads and mount the caliper. Replace the front wheel MAKING SURE THAT: the rotors are between the pads; the speedo gear engages the tangs on the gear dog; the spacer is inserted on the right side of the wheel on the axel correctly; after the axel in inserted all the way the pinch bolt is tightened AFTER the axel nut. Then check the wheel for free rotation. If it moves freely then spin it and apply the brake. If it stops spinning the pistons have moved into position. Release the brake and if it doesn't spin free you probably need to clean out your calipers. Gunk can accumulate inside them and around the pistons and keep them from returning to a relaxed position. Some brake cleaner on the outside rim of the pistons may work without the need to remove and disassemble the calipers. Most of the time it is required to rebuild the calipers. But that can be done in an afternoon.

NOW THAT"S WHAT I"M TALKIN ABOUT !!!

Thanks, these are all useful tips. I had no idea which way to go, other than just blunder around.

It wasn't doing it before I removed the wheel, so I'm going to carefully try and work the calipers, using a c-clamp. I'm also going back over it all to make sure it fits the diagram in my Haynes, in case a spaceer is mis-algined, and will check the caliper bolts, etc.

Will let you all know how it goes, and thanks all of you. I was pretty glum, not knowing where to go with it, and I just hate to have to bring it to the Man and pa for it. So far I haven't had to, other than the tire mounting, which, let's face it, is a bitch without the right equipment.

JC

If the brake caliper piston or pistons are still sticking after washing them, go out and get some 400 grit sandpaper and sand down the corosion or built up crud on them. If that doesnt fix it then by all means give it a try yourself to rebuild them. After all you are only pushing out the piston all of the way. Clean up the piston with either 400 or 600 grit sandpaper, apply a new o-ring on the piston. Be carefull when you reseat the piston, make sure you get everything lined up right and be carefull when you push the piston back in it's place. Just take your time and use a C-clamp, if you feel tension for any reason back off and reseat the piston. I have done this on a few bikes including my race bike. Its easy to tell if you did it right simply by seeing if it leaks after you have bled the brakes. Sounds really hard but if you keep everything clean and take your time and are carefull, you might only spend 10 bucks on a new o-ring and brake fluid instead of 60 to 100 bucks from the dealership.
A little front brake draggin is normal, when you turn the wheel by hand it should spin. It will come to a stop in a revolution or two depending on how hard you spin it. You should hear the brake pads touching the rotor. They are only a few thousandths away from the rotor. If the wheel is hard to turn then you have a brake dragging problem and that will need some attention. YOU do not want a front wheel locking up when you are going down your local canyon or freeway.
Sean

I would be pretty nervous about recommending sanding the pistons down and then seing if they leak. Front brakes after all are rather important, like life and death type important. Do what you like but this is one area where I wouldn't skimp - my recommendation would be to buy a new piston if the surface is rusty.
(It could seem to be OK but you work them the hardest in an emergency, and if that's when they start leaking, could be a problem.)
Jim

Hmm I guess I meant to sand the corrosion off of it. Sorry if I confused anyone. But even with 400 grit sandpaper it would take a long time just to sand a couple of tenth's of a thousandth off of it (.0001). All your trying to do is get to the shiny metal below the miles and miles of brake dust built up on the piston.
Sean

A couple of things to watch out for if you're rebuilding seized / binding calipers:

If you use sandpaper to clean the pistons, make sure you work around the piston face so any scratching wont make the seals leak. Never sand along the face (towards the pads) as this can make minute channels for the fluid to pass the seals. I used to put them up in a lathe, spin them up and use 800 grit wet and dry to clean them. This is almost like polishing them. If there is pitting or heavy corrosion on the piston, it will need to be replaced. Also watch out for any "crease" marks on the piston. This means the piston is not moving square in the caliper and possibly getting jammed against the caliper wall - which may require a whole new caliper assembly.

Secondly, a seized / binding caliper is often the result of corrosion behind the seals. The corrosion swells in the channel and forces the seal against the piston. Ensure you clean out any corrosion in the seal channels before re-assembly. I've got a set of old wheel spokes that have one end sharpened down to a point that are great for this stuff. I grind them down on a bench grinder, bend the pointy ends in a vise and you can get them into the channels to scrape out the corrosion.

Above all, make sure everything is absolutely CLEAN before you re-assemble. Buy some brake cleaner for this purpose - it's the best.

Like Sean says, it's heaps cheaper doing this yourself than getting a shop to do it - mainly because there's a fair amount of labour involved in cleaning everything. It's not hard, just messy / a bit tedious.

Good luck!

ALL these comments in this discussion have been helpful. Tomorrow I tackle it all, and will give you the results. I do suspect I'm going to have to clean the piston area at the very least, but diving in tomorrow...

Thanks guys.

JC

What was the gremlin??