Oberon slave cylinder used in the TTS kits

[ant]

Having clutch problems with a leaking slave cylinder. Looks to me like a O ring has failed. I know most of us with the Oberon Buell 1125 slave cylinder used on TTS supercharger kits have had a few problems.
The latest problem for me was i noticed a lost of clutch fluid. On further investigation the O rings on the cylinder body have swollen. I had a problem with a leak years ago and turned out to be a
damaged O ring. That was quickly sorted with a FOC seal kit sent directly from Oberon. I have been in touch with Oberon and they have had not had any issues with the O rings swelling. I asked about the fluid i use which is Dot4 and that's what they advise to use.
Posted a couple of photos. The first being the O rings no longer fit the groves. The second photo includes the Seal kit i replaced where one of the O rings is much smaller. The top two O rings in the second photo have clearly grown in size.

I have sent copies of the photos to Oberon and now waiting for a reply.

Any owners having or had any similar O ring issues. Or am i just barking up the wrong tree.

 

[Kevin frazier]

@R-III-R Turbo im almost sure had this same issue and figured it out iirc.

 

[R-III-R Turbo]

Correct Kevin I cannot believe they are still using Viton o-rings, they are incompatible with DOT4.
You need to replace them with EPDM versions. Hard to find but the details and links are all here.
all this was fed back to Oberon some years ago, I hope they listened and yours was just sold before.

 

[ant]

Thanks for you reply Art.
Strangely Oberon are still saying that they are unaware of the issue. They did however say that they would look for alternative O rings.
I have told them of the issues here on the forum and your finding the EPDM version O rings.

Ant

 

[R-III-R Turbo]

Thanks for you reply Art.
Strangely Oberon are still saying that they are unaware of the issue. They did however say that they would look for alternative O rings.
I have told them of the issues here on the forum and your finding the EPDM version O rings.

Ant

Oh they were 100% told about it since I pointed it out in 2019, and perhaps earlier if someone else did.
When did you get your kit?

 

[ant]

Hi Art,
Thanks for your reply.

Oberon sent the new replacement seal kit out to me on 04/02/2020 so they would have been fully aware of your issue. At the time they said it was unusual for the slave cylinder to have an issues so check for burrs in the casing as these could damage the o rings.
The last email that i received back from Oberon said leave it with them and that they would search for alternative O rings for me. The last email i sent them was to say that a
member on the RCO club forum had similar issue with the O rings and i included one of your photos. So the Cats out of the Bag.
So Oberon are still supplying the Slave Cylinder kits with Viton O rings.

Look like i need to find EPDM version O rings.

 

[R-III-R Turbo]

I bought from ze Germans but this low cost UK source seems to have come up since.
Though the actual item location is China so delivery time will suck vs. Germany.
Just watch out they sell by OD rather than ID so allow for that.

O-Rings EPDM Rubber 2mm Cross Section O Ring Sealing Washer Gasket OD 5mm-170mm | eBay

Material: EPDM Rubber. Cross Section (CS): 2mm. It's Quick, Easy, and Secure.

www.ebay.co.uk

Measurements of Oberon slave & their inadeqaute Viton o-rings (note these are swollen o-rings from their reaction to DOT4 - I've found 2.0mm gauge o-rings work fine). IDs of the 2 rings needed are 46 and 44mm. Note again those UK lads above seem to sell by OD not ID.

 

[ant]

Thought i would post the drawing that Oberon sent to me with the seal kit. Thanks for the link if they worked for you then i will ordered a set.
Thanks for your help.