The 'E' Type Forum

What are the salient functional differences between C24625 the servo for the Series 1 and C33564 the servo for the S3 V12?

I'm looking at a servo that doesn't work properly at present which seems to possibly have a mix of internal parts from both types of servos.

Are the two servos (correctly assembled) interchangeable? If not, why not? Both cars seem to use the same master cylinder.

I guess the problem is that I have no personal experience with S3 cars.

The later servos used on s2 and s3 cars have an external band joining the two halves of the vacuum chamber together, rather than the spigot fastening used on s1 servos. This makes the later ones much easier to dismantle

So otherwise they're interchangeable?

As far as I know, yes. The S3 may be slightly more powerful, i.e. have a slightly higher boost ratio , but otherwise I think any of them will fit . Peter Crespin can probably give you a definitive answer as he has had all 3 types over the years