Excited to be getting round to bleeding the brakes on my 16 restoration turned to an almost existential crisis yesterday as I pondered all the combinations of Master Cylinder and Master Vac's that came with the R16 over the years .
First problem was trying to mate a series 2 vac with a 17.5mm master cylinder. I thought it was a series one vac because it had two mounting bolts (per early 16's) into the steering column. No, there are two, series 2!. One with two bolts and one with 4. Their rod's also look different but probably measure the same. So the series 2 vac appears to only mate with a single circuit 19mm master cylinder. I thought I'd try a 19mm tandem Master but Renault decided it would change the thread size on the rear brake line so it could not be threaded. I then incorrectly tried to mate it with another master cylinder marked suitable for TL 69-71 but that turned out to be a 20.6mm one. I can only assume early TL's (perhaps only in Europe were not fitted with a master vac?)or perhaps the info is just wrong and it only fitted a standard 1470cc Renault 16.
Anyway the upshot is despite all the confusion I thinks I've sorted it. I do have a series 1 Master Vac (which would be original to a 69TS) however it appears to be in poor condition. The two Options I have are
1. Use the Series' one Vac with it's 17.5mm Master
2. Use the series 2 Vac (with early bolting pattern) and wait for the 19mm Master ordered off eBay to arrive in March!
So enough meandering with background my question is what is actually in a Master Vac?, Can the be opened up and cleaned? The reason I ask is because the only early one I have has a lot of rust remnants fall out with a shake through the valve hole. It's not exactly a clean looking unit and was probably sitting somewhere for many years (Possible under water!), but it's the only one I have.
See photo's for a snap inside the valve hole. It appears it could be opened up at the back if the two halves were turned in opposite directions. Is this correct? Cheers.