Topic: Service early CB500 front fork and damper

[mca2]

I've just disassembled my front fork of my CB500k1. It was about time, because what came out was way less than should be in there and it was also black and thick.

As black mud appeared from within the damper i would like to further service this item. Yet before i start demolishing parts, is it even possible to remove the lower cap? And can you service this damper or disassemble it at all?

[goldarrow]

IIRC, 6mm Allen using impact driver.  I find it easier to remove the screw while everything was assembled.

[wowbagger]

It looks like you already got the allen bolts out. Those caps should just slide off once the bolts have been removed from the bottom. There is no way I know of to disassemble the dampers any further. Mine had clogged with old, hardened grease and were not working correctly. I put them through the sonic cleaner and pumped the hot cleaner fluid from the sonic through them to get the old grease out. I thoroughly rinsed them out to get all of the degreaser out of them. I then filled a cup with brake fluid high enough to cover the lower holes of the damper and then pumped them over and over until the inside of the damper was full of fork oil and the plunger moved smoothly again. I drained the excess oil, reassembled the forks and filled them with the specified amount of oil the manual calls for.

My from forks now work better than they have since I owned the bike. Good luck.

[wowbagger]

Yeah, definitely use proper fork oil. The weight is mostly a matter of preference. If you don't have access to a sonic cleaner, you could probably get similar results using hot water mixed with degreaser to pump through them.

[Deltarider]

It was about time, because what came out was way less than should be in there and it was also black and thick.

As black mud appeared from within the damper

Do not use engine oil but ATF or fork oil. BTW, I've just changed mine after some 15 years. It came out clean and not smelling. After that filled with 7,5 weight fork oil (resembles ATF) and I like it.

[mca2]

Thanks for your advice. Those caps seem to be pretty stuck but I'll give it another try.

I will try cleaning them further with petroleum, I don't really like the idea of water inside those dampers. I don't know what was in there before, but I assume the forks haven't been properly serviced since 20 years.

I'm planning to use Eurol 10w fork oil afterwards. http://www.eurol.com/nl/2-producten/458-eurol-voorvorkolie-sae-10.html