S Brake servo

[mmickgoodall]

Moring all.
You may allready know this. But no one I asked knew so. I have found that the brake servo used on the S1 is a Mk3 Fiesta unit which TVR mount upside down and use a SAAB 900 master cylinder on. I think you can also use the Fiesta master cylinder if you turn the servo around.

[nasz]

My mechanic tried that but wasn't confident that it would live up to the job! When he did mine, he quickly dismissed the idea saying he couldn't live with himself if something happened to the brake system while driving!

A mechanic with a consciounce!!!

[RichardR]

mmickgoodall said:

I have found that the brake servo used on the S1 is a Mk3 Fiesta unit which TVR mount upside down and use a SAAB 900 master cylinder on. I think you can also use the Fiesta master cylinder if you turn the servo around.

Hi Mike,

Glad you managed to find out in the end. Out of interest, do you have any idea why TVR bothered inverting the servo and using a different master cylinder rather than just sticking with the full Fiesta arrangement?

Cheers,

Richard

[mmickgoodall]

I havent found a reason yet. It all fits with a small amount of redrilling of the pedle box, and the bonnet still shuts. If I find something when the car is mot'd soon, or when i've finished putting it back together i'll let you know. Or if any of you know im all ears. cheers Mick.

[steve b]

I have tried it - I'm afraid it won't work for long before tha brakes jam on - I think it is because the V6 produces too much of a vacuum.

The servo used is SAAB 9000 - I fitted one from a scrappy a few years ago and it has been fine, the original rotted through.

Sorry to be the bearer of bad news!

[mmickgoodall]

Thanks for the info Steve. Ill bear it in mind. I havent started the engine up yet as she's still in bits after the winter chassis rebuild. But it will only be a few more days and ill check what you say.
Although yours may have been different, as I have visited the local SAAB breaker and the servos were different to the one on my car even though the master cylinder was the same.
Cheers Mick.

[shpub]

The real reason (I suspect) is that the Fiesta master cylinder does not have a very big cylinder bore. As a result the overall breaking performance is severely changed because not enough fluid can be pumped into the callipers.

I would check that the bores are the same and if not remove it. Brakes are rather critical.