Front brake caliper won't close?

I took apart my front brakes to replace them and long story short I was sent the wrong pads. Compressed the caliper down all the way, finally got the correct pads and put them on. I bleed the brakes and get the air out of the line until pure brake fluid pours out when i loosen the bleeder screw. I then tighten it and constantly pump my brakes - nothing. Won't compress, no resistance on the brakes.

 

Sounds like caliper rebuild time; master cylinder too if you haven't already.

Original brake lines need to be replaced too; they were only supposed to have lasted four years. If you still have the original lines, they're dangerous.

You can't just replace the pads in 30-year old brakes and expect them to work correctly; they won't.

Your actual problem is either a stuck caliper piston (from pushing it in too far) or a master cylinder seal issue.

But you really need to completely rebuild the brakes. Your life could depend on it.

 

Ok, rebuilding the master cylinder is no big deal. Brake line seems to be ok, fluid comes right through, but i can replace that too.

the caliper worked fine. I was sent the wrong brake pads, so with a c clamp i compressed the caliper down until i BROKE a c clamp, and then tried to get the WRONG pads on, so the thing was REALLY compressed. Now it won't budge. I look at rebuild kits for calipers and all it shows is the metal band and the rubber gasket that goes around the caliper. That won't do anything if i replace that. Can anyone link me parts i actually need to get my front brakes to WORK?

http://www.ebay.com/itm/1x-XS400-XJ650- ... 918wt_1397

this ^ wont do anything. I have the rubber gasket already in good condition, and the metal band around it. Not sure what the third piece is.

I'm tired of spending hours on end researching and working on my bike and it still doesn't operate properly. All i want is to get the thing in OK condition to ride down to the yamaha dealer and have them service it, my time is too valuable and i dont HAVE the time to spend doing 5-10 hours of research + work on my bike EVERY day.

My bike has 14000 miles which is NOTHING for being 30 years old and yet i've been told a list of so many things to do on this bike to have it run properly it'd be better off to either A. be junked or B. given to a mechanic to fix.

Any help to get the front brakes to work and i'm good. Thanks

 

I'm 90% sure my caliper piston is jammed in and I have to replace the entire caliper. The brake fluid goes through the line perfectly fine and I bled the brakes with a bleeder kit to remove all air from the line. The piston will not come out because I was sent the wrong brake pads and compressed it so much that it's now broken. So I assume i have to replace the entire caliper.

At least the bike runs well after i did carb work, but now i have no brakes. Gotta replace the entire caliper and go from there..

I took an air hose and put on the bleeder screw (i read to try this in my bike manual) and sprayed air in attempt to get the piston to pop out. It makes a very tiny movement but is JAMMED in the caliper. I even tried using needle nose pliers while spraying the air through the caliper - nothing. Won't budge.

 

Do a forum search on "grease gun trick." It's NOT broken; you've got it jammed.

AIR WON'T WORK.

You need to pump something that WON'T COMPRESS into it-- air compresses.

Plug the hole for the line with a plain bolt, but leave it loose. Attach your grease gun to the bleed nipple and pump it full of grease until there's no more air and grease comes out around the bolt. Tighten the bolt and continue to pump; the non-compressible grease will force the piston out and make a big mess.

Ya know what else won't compress? Water. You could also fill it half full of water, plug both holes and heat it with a propane torch. This is the "exciting method" which can blow a hole in your garage roof and permanently damage your hearing. **NOT recommended, I'm kidding.**

Use a grease gun. You'll need to rebuild any caliper you find on eBay anyway.

 

If there's any air in there at all, it will compress rather than move that caliper piston. Just acts like a spring in the line.

If it worked before but not now, either the piston is now cocked and/or jammed in the bore, or there's still air somewhere.

Hard as these are to bleed, I vote air first.

 

They like to get air trapped in the line unions up on the fork, and at the master cylinder when you take a caliper off...it just works up into every high spot it can find and sticks there.

 

I see I'm a little late here...sigh.

Compressing a piston all the way shouldn't cause a problem, unless you used something that doesn't press straight in, like a channelock pliers or something instead of a c-clamp centered on an old pad straight with the bore...pushing in crooked can jam them, and screw up the bore too.

When replacing pads I'll usually pump the piston OUT a little ways, pull the dust boot back and flush the exposed piston and boot with brake cleaner or wd-40, and maybe dress with crocus cloth if it's rough...so you're not pushing all that trash back through the seals when you compress to put the new pads on.

Hindsight, but remember next time...

 

So i wake up this morning, my dad was supposed to get the grease gun off of my brother and I would get the thing fixed today.

Instead, my dad decides "That grease gun trick sounds like it won't work" and brings the caliper to a motorcycle shop to work on all weekend, i probably wont have the thing back until tuesday, and they probably wont even know what the f**k to do.

So when I go down there to pick it up, he's footing the bill, or if they break my caliper, I'm screaming in the shop owners face until I have a new caliper in my hand. They better know what they're doing to get the piston out or I'm going to be pretty pissed.

That's the last time I put one of my motorcycle pieces into someone else's hand and sleep on it. Figured I'd be riding today. Nope.

 

The grease gun trick never fails.

Sorry to hear that. You still need to do everything else I listed. The brake lines deteriorate from the inside; "passing" fluid is not a concern. POPPING A LINE under hard braking IS.

The caliper and master cylinder seals were supposed to have been replaced every two years. The hoses every four years. Any "designed in" margin of safety has long passed; those parts need to be replaced, period.

You've been told the truth, by people with experience doing this. It's not the 14,000 miles; it's the 30 years. This isn't a CAR.

The fact that it has so few miles just means that it's WORTH putting all of the work into. It DOESN'T mean that the work isn't necessary; it very much IS. If the bike is in good shape, it shouldn't be "junked." If you're not up to all of the necessary investment and work to make it safe and reliable, then passing it along to somebody with the resources and desire to do so is possibly a better course of action.

Unless you're up to "Option C"-- learning to work on it and doing it yourself.

Keep in mind that it will still need to have its valves checked/adjusted every 5000 miles, and will need the carbs cleaned, serviced and adjusted to keep it running properly. You'll need to learn this stuff, and you'll need a service manual.

Now, how about while you're waiting for your caliper to come back, you have a peek at the REAR BRAKE SHOES: http://xjbikes.com/Forums/viewtopic/t=15874.html This is important.