Series 1 master cylinder unions

[Dunc]

I tried to fit a series 2 spec master cylinder to a series 1 spec car (a 1976). Although the pipes are new, it seems they have different sized unions fitted? Whereas the S2 has the same size of port on the master cylinder front and rear.

Has the previous owner dropped a clanger and fitted the wrong size of union, or are the ports a different size on the front and rear of the series 1 master cylinder?

[oilmagnet477]

Dunc

Lotusbits lists 1974-76 Master Cylinder and 1976-82 Master Cylinder so it could well be that they are different (metric v imperial perhaps?)

http://www.rdent.com/manuals/index.html if you select 'Elite/Éclat' and 'Brakes' this gives some more detail but I'm struggling to decipher any more re- sizes as both seem to indicate 0.875"

S1 A075J6051SF Type TVCV 0.875"

S2 A075J6083F Type AS/AS 0.875"

 

Hope that helps?

Is there any way of identifying the old one? Was it defo original?

[Dunc]

Yes - when you zoom your picture, it shows the one to the rear is of a thicker thread than the one to the front, which matches the pipe set up on my 520. I'm 99% sure on the S2 variant, they are both the same size (I think M10). No biggy however, I'll just change that pipe for one with the correct size of union for the master cylinder and fit the S2 unit, which I think has a fractionally larger bore.