Seized Rear Caliper HELP!

Well Had my first brake down on the Mille! Bloody rear claiper seized on! In my years biking I have never had a caliper seize on.

Any ideas what the problem is.
fluid OK, Pads look ok. I will be riding then the bike will get slower until I can not move the back wheel. Then if I leave it for about 30 minutes or so for the claiper to cool down im off again, well until it happens again.

Going to strip the caliper down tonight and see if anything is broke etc.

Joys of biking I guess lol

I had this recently although not quite as extreme. I slackened of the rear brake slightly and it's sorted. It all hapened after bleeding the rear brake. Have you done the same? If you did make sure you used the correct fluid mucker.

Too much fluid or incorrect pushrod adjustment on the M/c.

It's possible to block the return hole to the M/C if the pushrod is wrong and you will basically pump out the brake pads and they not return.

If you have no fluid espansion room in the resevoir that can also do it as it will expand with heat but have nowhere to go except push the pistons out.

Good luck chap.

spoonz said:

Too much fluid or incorrect pushrod adjustment on the M/c.

It's possible to block the return hole to the M/C if the pushrod is wrong and you will basically pump out the brake pads and they not return.

If you have no fluid espansion room in the resevoir that can also do it as it will expand with heat but have nowhere to go except push the pistons out.

Good luck chap.

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Pushrod? this being in the master cylinder?

It's the rod passing through the dustboot into the M/C If it can't come back far enough the M/C piston will not uncover the fluid return hole hence the brake locks on.

spoonz said:

It's the rod passing through the dustboot into the M/C If it can't come back far enough the M/C piston will not uncover the fluid return hole hence the brake locks on.

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Not to sure what it is. Might make sense when I look at it tonight I hope

Ring the Guiness book of records to tell them you've a back brake that's stopped a mille

mark58 said:

Ring the Guiness book of records to tell them you've a back brake that's stopped a mille

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:biggrin your on form this week Mark :thumbup


Could it be the pistons just gummed up with road grime ?

Well stripped the caliper tonight, Pistons all free. Changed the pads and re-greased everything. The fluid was just over max and the rubber thing in the it was not folded up. sorted that and also ajusted the pushrod. Justed the pushrod tomuch. no brake at all now lol.

Just going to tweak it a little then take it for another test ride

Garvey bud, i'd put money on Spoonz' pushrod problem causing the seizing as it happened to me when i changed the rear disc for a wavey item.definately check that route first dude:thumbup

Hey Garvey - is that your first Aprilia rear brake malfunction? Yey, you bust your cherry! Well done mate!

A303 said:

Hey Garvey - is that your first Aprilia rear brake malfunction? Yey, you bust your cherry! Well done mate!

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Bust my Cherry lol, Yeah and I bust my master cylinder too.

Adjusted the pushrod to 1.5 - 1.0 differance as stated in the Aprilia Bleeding notes.
When I push the level I feel the presure then it carries on to the floor. maybe I have just bust the value in the M/C?
Maybe air in the pipe? only removed a little fluid from the resevoir and cleaned the caliper.
Anyways I have NO brake now lol. atleast it will not seize on the way to work.
Got to sort it asap.

Any more ideas guys?

Just reading the bleeding procedure. im alittle confused no the location of the caliper?
Do I bleed in position then change it and rebleed or do I rotate it?

Rear caliper

Hi, Garvey, I would like to help you on this. Here's what's happening. You definitively have air in your system, this is why the more you go the more the brake is applying itself. The air as it heat's up expand and apply pressure in all direction, since the only place that move is the pistons in the caliper... what follow is a rapid cycle of increasing pressure within the system. If you try to bleed the system as it is install on the bike, you will get nowhere even if you spend all night, cause the air trap at the highest point will just stay there. What you need to do is this. Remove the caliper from it's bracket and move it in such a way as to bring it at the highest point possible, you may have to unbolt the retaining clip under the swing-arm. Bring the caliper near the seat and hold it in such a way as to have the nipple at the top. Wait a few minutes so the air has the time to rise to the top, when bleeding go slowly and make sure it does not fall on the paint. When sure all the air is out, just put everything in place and you should not have any more problem with this, if you do have problem's to a lesser extend, it will be because there is still some air in it. The day all the air is out, it's end of problem,period. Hope i'm clear, if not, feel free to ask! If the braking line was transparent it would be easy to see that you have air and were it is. But it's not, so you have to work like you're blindfolded. Good luck.:thumbup

Hi all,

Well I bled the brakes all day. No brakes! I then noticed that some fluid is dripping from the m/c where the pushrod goes in. Im now guessing the m/c internials are stuffed.

Bled the brakes about 30 times today and used a couple of litres. now nothing is pumping through.
Week three of owning this bike and still in the poo! come back my zx9, alls forgiven lol

anyone got a spare m/c cheap? watching one on ebay

starting to hate Aprilia! Just called to find out about a m/c repair kit and I can only buy the m/c. also I thought I would replace the seals on the caliper and again only buy the caliper! what a con.

All my other bikes I could buy theses items. Oh well best get ebay and get my secondhand parts

Don't be discouraged mate. All the hassles are worth it in the end.

A303 said:

Don't be discouraged mate. All the hassles are worth it in the end.

Click to expand...

bit late for that one lol, its on fire in the garage as we speak. no just jesting! Just don't understand why the parts are listed on the parts screen but you can't buy them....

Anyways, still no rear brake and wondering whats next to do?!? replace caliper? replace m/c? Just found the m/c replacementr rsvr.net for £45 which seems a good price.
The wfie is not happy with me as I spent a lot of money on my last bike which I then sold to buy this! she said and quote "I don't understand why you would sell your old bike for a bike that doesn't work?!" lol bless her. she will get it one day. My 4 year old son said to me, Daddy don't worry, you will fix it and its a lot better than your old bike. thats my boy

Going to strip the system down again tomorrow and have another crack at it. see what happens.

Garv, dunno whether any of this is of help.
http://www.clubaprilia.net/forum/forum_posts.asp?TID=5316&PN=5

Fusebox seems a good bloke to talk to.

If you can get it sort of working I know that the 'hang a weight off the lever' trick does really work so might be worth trying to get the final few bubbles out.

And maybe your wife should talk to mine about her "but you 've spent all this money so why does it need ...?" questions. Bless 'em.

Hi Garvey, I see that you still have problem with the rear brake. What kind of oil are you using Dot4 or what? Last year I was trying to bleed the brakes on my SV and coun'nt get it to pump nothing, I was trying to use DOT5 but it woud'nt work when I start using DOT4 it all went allright. Once there is a lot of air in the system it can be very hard to get it to pump. Go at it calmly and methodically, you will manage. Cheers.