master cylinder gasket

[RTSE440]

Hello all just wondering if a 69 charger power boosted brake system had a gasket between the master and the power booster the 1st reason i ask is my fire wall gasket kit came with 2 of the master cylinder gaskets. one is a white foam type sealing type gasket but the other is a thin grey gasket material same as a water pump type gasket and the 2nd reason i ask is my parts book list all tandem type boosters as having one. Any input would be appreciated

[ODZKing]

Not sure if this will help but my 73 MS leaked and I determined it was the gasket. I couldn't find one anywhere. after some research I discovered it was the same MS as on Ford Mustang's and everything for them is available. Ordered it, (in fact 2 just in case) and worked perfectly.
So in answer to your question I think, I believe it is supposed to be the rubber type, not foam.
Parts book shows the same gasket for all models the same.
drum brakes is 2823994
disc brakes is 2881512
drum example below
https://www.ebay.com/itm/333571748900

Hope that helps

[RTSE440]

Sorry you must have misunderstood what i meant but this is a picture of the paper gasket  i have put between the master and the booster i figure it may stop dust and road grime getting into the booster or the master cylinder bore when pedal in depressed i suppose whats the worst that could happen having it there.

[RTSE440]

I get that this foam one fits on a non boosted master cylinder to seal the firewall but the paper gasket ?

[John_Kunkel]

Check this video at about the 2:30 mark and he discusses the gasket under the MC. Says don't use.

https://www.youtube.com/watch?v=lQs5KNiqOuU

Not sure if he's right, though; notice the indentation in the face of the booster that would allow fluid to drain, even with a gasket.  

[jlatessa]

Is that slot possibly a diaphragm air release?

Joe