Oberon Slave Questions

Hi everyone! My first post is a technical question (after much lurking around trying to find the answer). My 07 SD started seeing some leaks coming from down below the slave, so I did some searching on here, found out it was a common problem and then ordered an Oberon unit from www.motowheels.com

What's odd about the part that I received is that the instructions are different from Oberon's website-- it doesn't mention anything about the ball bearing under the cap. It's clearly the Oberon part, but it appears to be an older version. Did an early version of the Oberon slave cylinder not come with a bearing?

I ended up installing the new slave and fully bleeding it and of course it 'drags' when you put it in gear with the clutch in. I assume I need this ball bearing or some kind of spacer to make it fully disengage.

Thoughts/words of wisdom greatly appreciated!

-Mark

There is a thread somewhere from when I fitted mine years ago.

The same thing happened to me. If your Oberon unit doesn't have a ball bearing then it won't work. The ball bearing will be stuck in some grease inside the little plastic cover that came with the unit. When I got mine I took the cover off and threw it away not realising that the ball was stuck inside it. After many hours on this forum I eventually deduced what had happened, went to the bin and found the little cover and there was the ball. After refitting the slave unit with the ball everything worked like a dream and has done ever since.

Hope this is the answer you're looking for.

Thanks for the reply. I figured that the ball bearing or some kind of spacer would be needed. Why one was not included with my purchase is beyond me, hence my question: did an earlier version of the Oberon kit not include a ball bearing? If so, did they expect customers to reuse the factory one?

Also, has anyone tried rebuilding the factory slave cylinder with a new o-ring?

Call Steve at Oberon.

Mine came with a ball included.. As I remember it sticked to the plastic cover that you have to pull off.


It's just a bitch so bleed it, took me soo long

If you look on Oberon's site you see the following instructions with a "NOTE" at the top regarding the ball bearing and a list of the hardware included (ball bearing, (2) crush washers, and (2) bolts).
http://www.oberon-performance.com/acata ... ER3%20.pdf

The instructions I received does not have a "NOTE" at the top and the list at the bottom only mentions the (2) crush washers and the (2) bolts.

Anyways, I went to my local hardware store and found ball bearings (to my pleasant surprise)! They were in inches, but 5/16" comes out to 7.94mm. I'll give this a shot and see if it works.

Negative on the ball bearing from the hardware store. It fits perfectly into the bore of the slave, but there's not enough depth to then mount it to the bike (without compressing the slave significantly).

I will try to connect with Oberon on Monday.

Why don't you just call them to be sure? Maybe they sent you the wrong version.

I just replaced my slave in April and it came with
the ball bearing greased and stuck in it's place...
For good measure..I also replace the backing plate...
I didn't need it...but I always figure aluminium over
plastic and won't fail down the road....

So I've narrowed it down to a lack of throw in the slave. With the ball bearing in, the clutch is rock hard as the piston in the slave fully compressed; without the bearing, when you put the bike in gear and try to roll it with the clutch in it 'drags' badly. I've played with the depth that the slave is mounted and found that there's no sweet spot in the middle, hence the idea that there is a lack of throw. Does anyone know if the Oberon does have a shorter throw than factory?

I found the link to the thread where I had my problem. There are a few other links in there - maybe something that might help you.

viewtopic.php?f=18&t=15822&p=183602&hilit=+oberon#p183602

Well time to give a bit of an update. The rebuilt slave is still working perfectly ~400 miles later and not a drop of fluid has been lost.

"I see said the blind man"

Thanks for the link.

You are correct: Honda does have a high opinion of themselves, specifically their o-rings. The o-ring that is currently in the bike is from my local hardware store, but I ordered a few near the size I had measured and in some more exotic materials.

The size that you're looking for is under the AS568 standard, size -021. I ordered a few in Viton and BUNA-N Nitrile. Both of these materials are good with hydraulic fluids and with dynamic sealing; the Viton o-ring has a higher temperature tolerance. They can be found at the following URL's:

AS568-021 Viton:

AS568-021 BUNA-N Nitrile:

The key to doing this properly is that you must thoroughly clean out your slave cylinder. If yours is in fact leaking, it's because the factory o-ring has started to disintegrate. I took the slave cylinder housing and boiled it in disherwasher detergent--an excellent cleaning agent that is only activated at high temp, hence the boiling (word to the wise, don't boil it in a pot that your significant other enjoys cooking dinner in) . For the "piston" I took a solvent soaked string and ran it through the groove where the old o-ring had been. Reassemble with new o-ring, install, bleed the system, and make sure it's working properly.

-Mark