850 Master Cylinders

My Mk3 front master cylinder got a new seal kit about three weeks ago, bled up nicely and held pressure with no leaks.....until today.

Now that it's leaking my options are to send it to RGM motors for a 13mm conversion, or I can buy a NOS master cylinder at a very good price.

The downside is, it's an earlier 850 master cylinder; I've looked at Old Britts etc to work out what the difference is, they all seem to use the same seal kit.

Can someone please educate me, can I use a pre Mk3 850 master cylinder.....will it fit the Mk3 switch block etc?

Thanks.......Mick.........kettle738

kettle738 said:

.....will it fit the Mk3 switch block etc?

Click to expand...

Edit: Originally I thought not, however it would be possible to fit the pre-75 unit to the Mk3 switch assembly with some modification (a vertical slot would have to be machined/cut into the master cylinder casting mounting face)-but not vice versa, fitting the pre-Mk3 unit would move the brake lever position approximately 1/4" further away from the handlebar and four longer fixing screws would be required.

Many thanks for the prompt reply.......I think it's going to find it's way to RGM for a conversion.

Much appreciated........Mick........kettle738