Plea for advice from UK

OSCARMARK · Post by **OSCARMARK** » Wed Jan 09, 2008 11:23 am

Hi fellow CBXers,

I am new to the club having already joined UK Owners Club after buying my '79 Z in September 2007.

My problem relates to an incident a couple of months ago where my rear brake siezed rather spectacularly whilst exiting a dual carriageway. The system locked and slowed me down rather more quickly than I wanted to and fortunately in a straight line.

The rear disc was literally 'red hot' the splash guard had caught fire and melted away leaving a pool of sticky plastic. I had the bike recovered home and set about my investigation.

The rear master cylinder had siezed. The disc was heavily scored on the outside edge ( about 25mm ) and even after removing the calliper, I was unable to rotate the wheel without some effort. The disc was fouling on the "V" bracket. If you looked from the rear of the bike, instead of the disc running through the gaps in the bracket ( where the calliper mounts ) it was rubbing against the outside edge of the bracket.
I realised that the disc may have been damaged by the heat.
Courtesy of the UK Chairman Mel, I was able to source a replacement disc and bracket.

In the meantime I re-built the master cylinder, new seals piston etc along with the rear calliper, I replaced the brake line with a black sheathed braided one and even replaced the pipe from the reservoir. After painting the parts where necessary, I re-assembled everything .... but found that the new disc is making contact with the new bracket exactly where the old one had. The wheel could be rotated, but there was slight resistence.... this was without the calliper fitted.

I have taken the whole thing apart, checked the disc, checked the wheel spindle, the position of the spacers... but still the same. I even replaced the tie bar that locates the V bracket..........

Any ideas??? I have sent some photos to "icoapixohio" which clearly show the problem.

I look forward to your observations.

Kind regards

Mark
Epsom, Surrey
UK
I stripped the whole system replacing

EMS · Post by **EMS** » Wed Jan 09, 2008 11:52 am

Welcome Mark!

Maybe there is something not right with the brake rotor-wheel interface. If I understand your description right, the brake rotor sits too far away from the wheel. Is there any paint or something like that on the wheel hub?

alimey4u2 · Post by **alimey4u2** » Wed Jan 09, 2008 1:58 pm

I'm having trouble finding the pics Mark, do you ( or anyone) have a link ??

OSCARMARK · Post by **OSCARMARK** » Wed Jan 09, 2008 2:26 pm

I am brand new to the club and currently reading the ways of getting my photos linked to my posts.........

I have submitted some photos to "ICOAPIXOHIO" the photographs illustrate the problem far better than I can explain.

In the short term, I can e-mail them direct to you, or does than go against protocol?

Thanks

Mark

alimey4u2 · Post by **alimey4u2** » Wed Jan 09, 2008 2:27 pm

E-Mail sent.....

alimey4u2 · Post by **alimey4u2** » Wed Jan 09, 2008 2:31 pm

Your e-mail came back as an error Mark, I will PM you with my e-mail addy. Look out for messages sent ( tile above)

Hi. This is the qmail-send program at yahoo.com.
I'm afraid I wasn't able to deliver your message to the following addresses.
This is a permanent error; I've given up. Sorry it didn't work out.

Terry · Post by **Terry** » Wed Jan 09, 2008 2:36 pm

I transfer my pics to, http://s70.photobucket.com/
and once there, I click on the HTML below the pic which saves it and then I paste it here. Seems to work prety well.

alimey4u2 · Post by **alimey4u2** » Wed Jan 09, 2008 3:06 pm

Photos from Mark.....

Terry · Post by **Terry** » Wed Jan 09, 2008 3:15 pm

Could the spacers be reversed on the axle? Everything would fit, just not line up correctly.

cbxtacy · Post by **cbxtacy** » Wed Jan 09, 2008 3:23 pm

Or the heat could have warped the holder?

alimey4u2 · Post by **alimey4u2** » Wed Jan 09, 2008 3:29 pm

Strange one this, Apart from the possibility of the bearings being incorrect or mis-assembled, I do wonder if the inner spacer (inside the wheel) has collapsed ?? Chain wear to one side may be indicative but a wheel that is off center would be proof ??

alimey4u2 · Post by **alimey4u2** » Wed Jan 09, 2008 3:30 pm

cbxtacy wrote:Or the heat could have warped the holder?

New disc & bracket George but that was my first thought....

alimey4u2 · Post by **alimey4u2** » Wed Jan 09, 2008 3:41 pm

Mark, Put the bike on the centerstand, straighten the handlebars, check the rear wheel for centerline by pulling a piece of fishing line on either side & comparing the gaps to the front wheel. I think you may find it may be offset to one side ?? Run a straight edge between sprockets to confirm. If that's the case you will need to dissassemble the rear wheel & inspect. Do you have a workshop manual ??

EMS · Post by **EMS** » Wed Jan 09, 2008 4:24 pm

If the rear rotor is the correct CBX rotor, with the correct offset, and there is no problem with the mounting of the rotor to the wheel, the collar (shown in the picture as no. "8") is the only part that determines the location of the caliper bracket relative to the rotor.
An easy remedy would be to add a large washer on the rear axle between the spacer and the caliper bracket to move the caliper bracket outwards a few milimeters.

alimey4u2 · Post by **alimey4u2** » Wed Jan 09, 2008 4:35 pm

Thanks for the pic Mike, that definitely helps......

Now if the datum of item 3 ( bearing retainer) had moved "in" due to ( lots of scenarios but I'm going with collapsed item 11 [ bearing spacer] ) This is the same datum that contacts the brake caliper support bracket.....

Could be off track here though....Not a Comstar expert..

The International CBX Owners Association

Plea for advice from UK

Plea for advice from UK

Trying to get photo's posted