Hydraulic clutch release went pop

Well that sucks. Out of interest, where did you get the o-rings from (that are in it right now)?

Perhaps replacing these is just something that has to happen periodically.
Interested to see your photos and what went wrong.

I did trace back what did happen the first time with mr. Oberon. That time (end of 2018) I got the first issue with the Oberon clutchpiston (that blue part with its spring inside the housing) Fluid was entering into the room between piston and the small covercap. Cause : the black oilseal (not that grey one)of the piston was broken and partly eaten by the Dot 4 fluid. I did send Richard of TTS a picture of the damage and did ask him for a newbee. Instead of that oilseal he did send me 2 small strings of 2mm EPDMrubber in order to fix those ends together into 2 o-rings. But I did ask for that oilseal. The 2 o-rings seem to be ok that time. At last, after some confusing emailing he did send me a complete new Oberon clutchunit for free. Things went well for about 3/4 K km (I'm just a shunshine captain) about 2 years of time.
Today, after uninstalling the Oberonunit out of the TTS clutchplate bracket I did observe that both outer o-rings of the cylinder were considerably larger (did stretched itselves). One of the o-rings was partly eaten by the fluid. On the other hand, the piston oilseal was rather ok. Not totally, but ok. So, now I'm busy in looking for newbees o-rings which are Epdm. I still get those rubber EPDM peaces of string but but that does not seem to me to be a long term solution.

Ah so your 2 failures were all the Viton rubbers from Oberon then?

I think these are the EPDM rings I got to replace the Viton ones that come with the Oberon slave cylinder.
Sealing Ring/O Ring 42 x 2,5 MM EPDM 70, quantity 2 Piece | eBay

R-III-R Turbo said:

Ah so your 2 failures were all the Viton rubbers from Oberon then?

I think these are the EPDM rings I got to replace the Viton ones that come with the Oberon slave cylinder.
Sealing Ring/O Ring 42 x 2,5 MM EPDM 70, quantity 2 Piece | eBay

Click to expand...

Yes, all the Vitonway... And noo ! don't get those german rings cause 2,5 thickness won't fit ! If you install those onto the pistonhousing you cannot push the housing into the TTS clutch bracket. How do I know ? I did try that before with same size O-rings I did get from a hydraulic company And second : 42 won't fit either, dia is too small , the dias of the o-ring housing grooves are about 45,95 mm. If you are still riding with the Viton rings : STOP riding. Otherwise you will get -as you are probably familiar with that-a mass into the engine one nasty day cause of the fluid when the Oberon rings pop out again. I'm going to check the sump pan inside cause after draining the oil into a container and after it stayed for a while in there I did notice that the oil at the bottom of the container look like muddy.
Meanwhile I did order at the 'Diehr & Rabenstein' company the right sizes epdm O-rings (Tnx)

Can you tell me what is the part number for the correct orings for dot4 .
Mine have been ok but better safe than sorry . Cheers

Pedro said:

Can you tell me what is the part number for the correct orings for dot4 .
Mine have been ok but better safe than sorry . Cheers

Click to expand...

Part no : 458055 My fault. Sorry for that. I got those o-rings from Germany yesterday. Today , it would be a piece of cake to fit those guys. Just simply slide the black cylinder with its fresh o-rings into the (TTS)clutchbracket. (Slave already put into the cylinder) No way. What the heck ? If you look very closely at the black cylinder you will see/measure that the (outer)radius of the cylinder at the front is a bit wider than at the back. So the surface of the cylinder is a kind of steppedwise from front(wide) to back.(narrow) So we need 2 o-rings of a different size. To-morrow I will contact a company who is selling Buell clutchparts. ( epdm o-rings ) Will be continued.

I got lucky with that company who also sell Buellparts. I only had to order the complete set of clutch rings/seals. They did assure me those are all Epdm. Now waiting for the postman, he will ring twice.

fastfun said:

Yes, all the Vitonway... And noo ! don't get those german rings cause 2,5 thickness won't fit ! If you install those onto the pistonhousing you cannot push the housing into the TTS clutch bracket. How do I know ? I did try that before with same size O-rings I did get from a hydraulic company And second : 42 won't fit either, dia is too small , the dias of the o-ring housing grooves are about 45,95 mm. If you are still riding with the Viton rings : STOP riding. Otherwise you will get -as you are probably familiar with that-a mass into the engine one nasty day cause of the fluid when the Oberon rings pop out again. I'm going to check the sump pan inside cause after draining the oil into a container and after it stayed for a while in there I did notice that the oil at the bottom of the container look like muddy.
Meanwhile I did order at the 'Diehr & Rabenstein' company the right sizes epdm O-rings (Tnx)

Click to expand...

Yeah I got a heap of O-rings from Diehr and Rabenstein, can't remember which ones were the right ones after, but they do many many sizes in EPDM. The one set I photographed is probably not the right one and mislead. But they do the size rings needed to fix this.

The 2 outer o-rings, between the slave cylinder and the TTS clutch cover housing that it sits into, are also different sizes, easy get caught out. One is 46mm and the other 44 or something.
I must draw up an illustration to ensure anyone following this in future gets the right sizes.

The OEM Buell slave, will it have the exact same o-rings as the Oberon version?

R-III-R Turbo said:

Yeah I got a heap of O-rings from Diehr and Rabenstein, can't remember which ones were the right ones after, but they do many many sizes in EPDM. The one set I photographed is probably not the right one and mislead. But they do the size rings needed to fix this.

The 2 outer o-rings, between the slave cylinder and the TTS clutch cover housing that it sits into, are also different sizes, easy get caught out. On eis 46mm and the other 44 or something.
I must draw up an illustration to ensure anyone following this in future gets the right sizes.

The OEM Buell slave, will it have the exact same o-rings as the Oberon version?

Click to expand...

Yes, there you go : 'or something'. You have to do the right maths in order to get the dias and thickness exactly otherwise you will not get the Oberoncylinder in the TTS clutch bracket/housing and
Yes, according to the Buellshop they are. I shall see to it to-morrow when I get the shipping.

fastfun said:

Yes, there you go : 'or something'. You have to do the right maths in order to get the dias and thickness exactly otherwise you will not get the Oberoncylinder in the TTS clutch bracket/housing and

Click to expand...

Says your man who thought they were both 45,95mm