Has anyone swopped out their single reservoir master cylinder for a dual master on ’66 Toronado? I know in ’67 Oldsmobile went to the dual master for the Toronado and RockAuto and others list the RAYBESTOS MC36236 dual master as a replacement for ’67 Toro and wondered if I can use this one on my ’66 without any other modifications other than brake lines? This particular Raybestos master is listed as being for both drum or disc front brakes, which my ’66 has the original drums. Anyone know if this would work?,,,thanks

 

The pushrod in the power booster is different for the dual circuit M/C, so you'd need to change that also to use the 67 M/C. The other option is to use the M/C from a 1962-66 Caddy DeVille, which is dual circuit but accommodates the longer pushrod in your current booster.

 

Thank you for the information. Rockauto lists a few for those years Caddys (see the screen-shot below) but have a footnote "Except Moraine Master Cylinder" which I'm not sure what it means; do they mean Moraine "booster", not master cylinder? And if that is what is meant, how do I know which booster I have, I believe my car has the original one from the factory in '66?

 

I found an ACDelco 18M1058 which is listed for the Caddy DeVille of those years you mentioned so it should work without any alterations; being this is a drum/drum set up, would you say a proportioning valve is necessary, I know they are needed for a disc/drum set up?,,,thanks

 

Normally four wheel drum cars do not use a proportioning valve. Ironically, the early Toros actually DO have a prop valve in the line to the rear wheels. I suspect this was due to the heavy front weight bias that could easily lead to rear wheel lockup in a panic braking situation. Your Toro should already have one. And more to the point, if you aren't changing the M/C bore diameter, there's no reason to change anything in the rest of the braking system. The wheels don't know or care if the M/C has single or dual circuits.