Clutch Pipe thread diameter help

[Themadmob]

Hi All

I am restoring a S3 and one of the items I have replaced is the Clutch master cylinder, however, when trying to fit part number 577687 - pipe from clutch master cylinder to flexible hose i noticed the thread diameter of the new pipe is to big to fit into the master cylinder ? .... it looks as though the new master cylinder has a smaller diameter hole ?

And ideas of what pipe i should get with a smaller thread?

Thanks

[crackers]

If practical (I don't know how far into the installation process you are), you could take the parts to a brake specialist in the hope of either getting a pipe that fits or an adaptor.

[gromit]

Depending on what year the parts are from they switched the brake connections from imperial to metric at some point.
I had a Series IIa recently that had a pipe made up with metric one end and imperial the other to overcome the problem.

I think (but need to check) that the metric fitting is bigger. If that's the case you need a later master cylinder or you have to make up a pipe to suit.

Just Google'd and I found 2 dates for the change, '71 & '81 . '81 sounds more likely, clutch would probably be the same.
http://www.dingocroft.co.uk/acatalog...s2and3-p6.html looks like '80 it changed to M10 x 1


colin

[jboot51]

My defender has an adapter between the master cylinder and steel pipe.
it seem s3 and defenders share the same master cylinder.
The adapter seems to be this,


Adapter - 3/8" UNF male to 7/16" UNF female


139082 Adapter for Pipe to Clutch Master Cylinder Series 3 and 101 Forward Control and 90/110

[Themadmob]

Ah fantastic jboot51 .... that's exactly what I need .. thanks

[gromit]

Ah fantastic jboot51 .... that's exactly what I need .. thanks

If I'm reading things correctly and the fitting is currently too big to fit into the master cylinder then the adaptor is the 'wrong way round', it's a reducer taking 3/8" UNF down to 7/16" UNF.

What's the OD of the fitting thread and does the other end of the pipe fit the flexible hose OK ?


Colin

[Themadmob]

Hi Gromit .. This is the fitting I need ... I have googled it and it seems a standard thing now as the permanent pipes have a bigger fitting so the adapter allows for the conversion to a smaller size to fit into the cylinder .. The other end is perfect and fits the flexible pipe

[Slunnie]

I read this thread with interest as I had the same issue but was not yet up to solving it.

In the end, I took parts to the local brake and clutch mechanics and they made me a new hose that had the required fittings at each end. It was $70 and done pretty quickly. They also did it as flex so I didn't need to worry about bending of the hard pipes. This hose replaces the flexible hose also.