SIERRA BRAKE SERVO, A MYTH?????

[greymrj]

If you have been taking an interest in the research aimed at finding an alternative brake servo/master cylinder set up you will know that I asked for info from other forum members, and I am grateful to several of you for your help. I now need help again on a slightly different aspect of this 'saga'. I am making this a separate post so as not to confuse the main research! I have seen several references to a 'Sierra' servo being fitted in some S types (for example mention in Steve Heath's 'bible' and in the Alternative Parts List). I am beginning to think that this was a (reasonable)assumption based on the braking system being largely Sierra based. I have now been through all the TRW (Lucas,Girling and Bendix) info and I cannot find any Sierra set up which matches the actual servo/cylinder set up which we have identified on a several 'original' late S types.
I am now pretty sure the source was a specific Fiesta Mk3 unit* rather than Sierra. I now need to confirm a few final points with the TRW technical guy. But before I do IS THERE ANYBODY OUT THERE who can throw any light on the 'Sierra' reference??? It would really help me if I can just rule this out once and for all.
(* dont jump to conclusions yet, there are several Fiesta master cylinders which look identical externally but differ internally!)

[Loubaruch]

Not sure where the servo originated but am pretty sure that the master cylinder on a 1990 S3 was from a Saab 900

Best of luck

http://bertram-hill.co.uk/default.aspx

[GreenV8S]

You're right, it has Sierra uprights hubs and callipers but the m/c is Fiesta (direct mount reservoir version) or Saab (remote reservoir version).

[Rockey]

Any help
http://cgi.ebay.co.uk/Classic-Saab-900-brake-maste...

[greymrj]

Thanks Rockey. That servo/master cylinder might be of use to someone but I am not yet sure if it is the correct one (the master cylinder looks to have 2 rather than 4 ports) so I have emailed the seller to ask for more details. If it is correct for an S then I will post accordingly.
Ideally need more responses from later car owners on the 'Sierra' issue!

[GreenV8S]

The Ford one is a Fiesta part, but it was used on lots of different models, and those same models use various different master cylinders that aren't all interchangeable. Hence you can't just march up to the counter and demand a 'Mk III Fiesta master cylinder' and assume it'll fit. You need to ensure that the bore and stroke match and the hydraulic fittings are the same. They're readily available, although the ones my local motor factors matched it to are visually quite different to the originals.