Help! (again...zzz)

Squiffythewombat · Post by **Squiffythewombat** » Mon Mar 17, 2008 12:47 pm

Hi Guys,

Firstly thanks, as per normal for the vast amount of help youve given me! The bike is ready for its MOT bar one thing...the rear wheel!

Bearings have been replaced fine, as has the tyre, however ive put the wheel back in and its ULTRA stiff, i mean i cant push the bike in neutral because its so stiff! It feels like the rear brake is binding but im not sure.

Has anybody got any ideas? i have the wheel out now and a paddock stand but cant seem to pin point the issue and i have the MOT booked for tomorrow!

Could brand new bearings make it this stiff? i replaced the drive bearing as well as the two wheel bearings, they did seem very stiff when i put them in however im sure they shouldnt stop the rear rotating!?

Is there a certain "technique" in replacing the wheel, have i got a spacer the wrong way round or something?

Any help would be great...

Squiffythewombat · Post by **Squiffythewombat** » Mon Mar 17, 2008 1:20 pm

Timbo wrote:Does it free up if you loosen the wheel nut?

You know you had the trouble with the bearing spacer, did it all go back in ok? ie no damage to bearings etc.

Just tried that and no, the bearing spacer fit in fine and i didnt have any trouble with the bearings!

I did notice that on the test ride that the rear brake didnt seem to work too well hence why i think its the culpret!

After lunch im going to put it all back together without the caliper and see if it moves ok, if it does then i know thats the problem!

this is SOOOO frustrating as im *that* close to having her back after 6 months off the road

Squiffythewombat · Post by **Squiffythewombat** » Mon Mar 17, 2008 1:21 pm

and OMG your post count is huge now..gonna have to start posting +1's!

Post by **sirch345** » Mon Mar 17, 2008 4:15 pm

Squiffythewombat wrote: After lunch im going to put it all back together without the caliper and see if it moves ok, if it does then i know thats the problem!

That's what I would try first if it's not obvious Toby

especially if what Timbo suggested didn't help.

Chris.

Zakalwe · Post by **Zakalwe** » Mon Mar 17, 2008 9:31 pm

Have you topped up the brake fluid or changed the pads? There might be too much fluid which means that the piston cannot fully retract?

Also, have you ptu the various washers back on correctly/on the right side? Check here

Squiffythewombat · Post by **Squiffythewombat** » Tue Mar 18, 2008 1:10 pm

Well the wheel spins perfectly without the caliper attacted!

The bearings, washers etc all seem perfect.

Now i cant actually get the pads to seperate using a screwdriver, the piston seems to be fully extended and i think its somewhat gooed up so im going to remove the pads and have a clean now. hopefully in time for my MOT

will keep you posted.

Squiffythewombat · Post by **Squiffythewombat** » Tue Mar 18, 2008 1:40 pm

I feel like crying!!!

Pads out and the piston seems stuck solid!

Should i be able to push it back in with my hands?

It defiantly doesn't seem to be moving freely and im guessing the only way to sort this out is to strip down the caliper?

Bearing in mind i dont have a bleed kit yet im guessing theres no way to do this without getting brake fluid everywhere?

Post by **sirch345** » Tue Mar 18, 2008 2:03 pm

Toby, you really want to free up that piston using the brake pedal if at all possible. You need to put a thiner something between the piston and the disc in stead of the pad, (leaving the other pad in place) so that it has a small amount of space there to come out a little further. Hopefully then you can ease it back and pump it out again but clean off any crud on the piston before pushing it back into the caliper. If you can move it in and out (ooh eer missus) a few times it should start to free up. If you can get it to move you may not need to strip the caliper. Fingers crossed for you

Chris.

Squiffythewombat · Post by **Squiffythewombat** » Tue Mar 18, 2008 2:09 pm

sirch345 wrote:Toby, you really want to free up that piston using the brake pedal if at all possible. You need to put a thiner something between the piston and the disc in stead of the pad, (leaving the other pad in place) so that it has a small amount of space there to come out a little further. Hopefully then you can ease it back and pump it out again but clean off any crud on the piston before pushing it back into the caliper. If you can move it in and out (ooh eer missus) a few times it should start to free up. If you can get it to move you may not need to strip the caliper. Fingers crossed for you

Chris.

As normal chris your a total legend! Thanks for taking the time to post that, i will try it after lunch and let you know! Ive booked the whole day off to sort this so fingers crossed!

(stupid question but how do i know its working at optimum performance? should i be able to move it back in with just my hands?)

Post by **sirch345** » Tue Mar 18, 2008 2:27 pm

Squiffythewombat wrote:
sirch345 wrote:Toby, you really want to free up that piston using the brake pedal if at all possible. You need to put a thiner something between the piston and the disc in stead of the pad, (leaving the other pad in place) so that it has a small amount of space there to come out a little further. Hopefully then you can ease it back and pump it out again but clean off any crud on the piston before pushing it back into the caliper. If you can move it in and out (ooh eer missus) a few times it should start to free up. If you can get it to move you may not need to strip the caliper. Fingers crossed for you

Chris.
As normal chris your a total legend! Thanks for taking the time to post that, i will try it after lunch and let you know! Ive booked the whole day off to sort this so fingers crossed!

(stupid question but how do i know its working at optimum performance? should i be able to move it back in with just my hands?)

Yes, you should be able to push the piston back by hand. Remember though in doing so will push brake fluid back up into the reservoir, so I would slacken the reservoir top slightly to let the air out. Also wrap an old rag around the reservoir body just in case you have any brake fluid come out.

Just in case you have forgotten, brake fluid will lift paint,

Chris.

Squiffythewombat · Post by **Squiffythewombat** » Tue Mar 18, 2008 2:41 pm

Cool, well the caliper is not attached to the back wheel right now. Ive tried moving it back and forth as you say however, while it has loosened somewhat its still very hard to push back in with my hands! (could this be because there is air in the system as well?)

Heres a couple of pics:

This shows you where it rests "naturally" and where it gets to if i pump the pedal!

(im really so sorry for being such a dunce on this one!)

Post by **sirch345** » Tue Mar 18, 2008 2:54 pm

Nice pic's Toby, well apart from the problem of course.

You need to try and lever the piston back in using something flat like a tyre lever or similar. Try to get it moving but make sure it moves evenly by putting pressure on one side and then the other of the piston, you don't want to jamb in the caliper by not going back in evenly. It looks like it's pretty far out to me, so I wouldn't pump it it any further. Try to clean the piston off first.

Air in the system will not effect the piston movement.

Chris.

PS. If you can't go and get some brake cleaner try a little brake fluid on the piston, it will help with the cleaning and should help free it up too. Make sure you wipe up any excess before re-fitting the pads.

Squiffythewombat · Post by **Squiffythewombat** » Tue Mar 18, 2008 3:19 pm

sirch345 wrote:Nice pic's Toby, well apart from the problem of course.

You need to try and lever the piston back in using something flat like a tyre lever or similar. Try to get it moving but make sure it moves evenly by putting pressure on one side and then the other of the piston, you don't want to jamb in the caliper by not going back in evenly. It looks like it's pretty far out to me, so I wouldn't pump it it any further. Try to clean the piston off first.

Air in the system will not effect the piston movement.

Chris.

PS. If you can't go and get some brake cleaner try a little brake fluid on the piston, it will help with the cleaning and should help free it up too. Make sure you wipe up any excess before re-fitting the pads.

brilliant, clean and clear advice, you should really charge for this chris! Thanks, will go and try that now...

Wicky · Post by **Wicky** » Tue Mar 18, 2008 3:46 pm

Looking at the pics your piston looks like it still could do, whilst pushed out, with a better clean up on the corroded areas. Try a fine wet & dry then autosol/toothbrush (rag round the awkward bits) so its smooth and polished up.

I use to easily ease back the piston a pair of pipe pliers (no 3) and some wood to protect the piston / rag the caliper.

Don't forget copper grease on the sliding bolts and take care with the ickle grub screw...

Good luck and if all else fails use the infallible Honda hammer:

Squiffythewombat · Post by **Squiffythewombat** » Tue Mar 18, 2008 4:26 pm

Right well its been cut short as the guy needs his paddock stand back tonight thus ive bolted everything back together, pressed the piston in as far as it will go and will ride to the bike shop tomorow without using the rear brake!

I'll have them take a look, they have all the tools and if it costs me Â£90 so be it, ive been without my bike for 6mths and its too close to let it go now!

I think, in the end, it was the pad on the inside (not the one the piston touches) thats rubbing so im not really sure whats going on...

...oh well i did the front pads, electrics and fairings myself so im more than pleased with that! Thanks for all your help guys, hopefully there will be a "it passed" thread tomorrow afternoon!