NC23 front caliper sticking....

[veefer400]

Hi all, having a few issues with the r/h front caliper on my '23... Gave the bike a clean the other week and whilst it was on the stands I noted the front wheel was reluctant to go round - but span freely after a palmthud or two to each caliper?

Aha. Time to service the sliding pins then... caliper was dually removed & the bracket cleaned, relubed and rebuilt.

Still same problem... removed caliper again, eased pistons out against an extension bar & carefully cleaned, lubed and pushed them back in, didnt look too shabby to be honest? Sliding bracket now has new sliding pins & seals, everything is rebuilt.

Nope. same problem... discs & pads are good, master cylinder isnt sticking in/on at the lever, brakes rebled with new braided hose a few months back in the Summer?

Fluid is midway between Hi & Lo in the reservoir, wheel will jam up on brake being applied, freeing on a palmthud to the r/h caliper - which would indicate to me pistons sticking/seal problems, master cylinder problems would cause both brakes to stick?

Just called DSS to check if this kit (P/no: CK CBR400RJ-K F)contains all eight seals, they are closed until the 4th...


WTH??
http://www.youtube.com/watch?v=kgpY_oGINU8

[Townsend87]

I have the same problem with my RH caliper at the moment to.. although it is only a problem in the mornings and frees off when it warms up after half a mile, so not a hugh problem.

For my bike my thoughts were the higher iron content in my after market RH disk which rusts over night in the damp weather we're having (parket outside under bike cover). Seems strange that you are having the same problem.. could be a common fault with nc23's?

[veefer400]

Maybe? The l/h caliper is fine, probably due a service dont get me wrong, just annoyed this has happened in the middle of the holidays - I have plenty of time to fix it but no parts as nowhere is open! If the local bike shop doesnt have any tomorrow I may have to run into Bristol & pay Fowlers prices for four seals...

Not bothered about changing the seals, quite straightforward - just worried about hassles bleeding thro again... I have a large syringe ready in the garage so may try this reverse bleeding technique...

[veefer400]

Sorted!



Dust seal in one pot had had enough, cue one sticky icky piston... stripped the lot out, cleaned pistons & rebuilt with red grease & new seals...

Caliper bled through real easy with the syringe!

Observe its thirst for bubbles...
http://s109.photobucket.com/albums/n61/ ... V04716.mp4

This was of course pulled thro the caliper, need to get a bigger syringe with a smalled end to try reverse bleeding - this should work even better coz you are pushing the air back up the hose which is where it is trying to go anyway...

http://cgi.ebay.co.uk/100mL-Syringe-Bra ... 077wt_1345

[veefer400]

Spangly new stainless pistons with the old Übergak standard ones...



DSS wanted £15 per piston, paid £18.99 + £2.95 postage for these two, good machining quality, fit and forget with the stainless...

http://cgi.ebay.co.uk/Honda-nissin-cali ... 500wt_1156

Will fit NC24, NC23, NC29, CB6 Hornet etc...

The old ones were past it tbh? Usable, dont get me wrong - but what with the plating corroded thro I would just have been waiting for them to scab up again?

All good at the mo - reverse bled them yesterday with the syringe, filled up in no time, saved a hour of swearing trying to push air out of the caliper...

[Wozza]

Good find. They look longer than the originals - is that just an illusion?

[veefer400]

Good find. They look longer than the originals - is that just an illusion?

Possibly? They are 25mm dia x 31mm length, I will check the originals in a mo... fit the calipers ok anyways!

[veefer400]

Yep - originals are 25mm x 31mm, the same...

[Wozza]

Excellent. I'll be rebuilding my calipers in the spring, might have to invest in these pistons!

[veefer400]

Excellent. I'll be rebuilding my calipers in the spring, might have to invest in these pistons!

Good call! Free listing day today on ebay, sell some stuff, lol