On my 1956 Lincoln premiere , the master cylinder is dead ,I have to defuse it but I do not understand how it works, can you explain to me ?
On my car I have this one

I would like to hnow if I can change it for this one ?

Is it the master cylinder that's bad or the vacuum booster? If it's just the master the one pictured should work as long as it fits your application. If the booster is bad they are available from various sources rebuilt. Try the Lincoln Old Parts Store, rockauto.com, Joblot Automotive or even eBay Motors.

Rebuild kits are available for the master cylinder itself.  I have purchased several from Kanter for about $60.  For the booster none are available.  You would have to send it to someone such as Booster Duey for rebuild.  The master cylinder itself is really quite basic in the way it works.  The push rod really doesn't "Push" the fluid rather than it displaces it.  Therefore the kit mainly consists of new seals and valve that separates it form the resevoir (sp?).  The booster itself isn't much more complicated.  The issue I've had  is with the leather seal drying up and sucking air.  I've always  softened it up with a little oil and then it works well for long time.  Other than that it just has a couple of poppet valves that open and close as the peddle is pushed/released to equalize pressure.  If you have a shop manual it explains it in detail.  If not I can provide scans.

The treadlevac system actually works quite well.  I've had to sudden stop my 57 Lincoln and have had the brakes lock up.  I 

Thanks for your answer , there is only the master cylinder is bad the vacuum booster is good
On rockauto there's some to sold but they are not the same of mine I do not understand why
have a look here : https://www.rockauto.com/catalog/raframecatalog.php?ck[year_1995]=true&ck[mkt_US]=true&ck[mkt_EU]=true&ck[mkt_CA]=false&ck[mkt_MX]=false&ck[viewcurrency]=EUR&ck[ID]=0&ck[idlist]=0&ck[PHP_SESSION_ID]=gcpmk1qp94iaqsa4769p8u34g3

Sory my linke is not good on rockauto they have this one

Thank you for your good explanation , no  I have not got shop manuel and if you can scans it , it's a realy very good help for me
Thanks for advance

The "master cylinder" on your Lincoln is actually a Bendix Treadle Vac power brake booster which has a built in master cylinder.  I am pretty sure that all Lincolns had power brakes.  The master cylinder that you say you want to go with is a non power brake master cylinder of the type used on Ford and Mercury cars without power brakes.  You cannot just replace the Bendix unit with the non-power brake master cylinder as cars with power brakes used a different brake pedal linkage setup than non-power brake cars.  You need to change the brake pedal linkage to do the switch to non-power brakes or better yet just rebuild the Treadle Vac.  The Treadle Vac is a good booster.  I have them on both my '54 Mercury and my '54 Ford police car.  Good luck, Alan S. Freeman

I would suggest trying the lincoln site, as these are more relevant to their cars than fords. The treadlevac system is far different to anything else.


  AussieBill            YYYY    Forever Y Block     YYYY

 Down Under, Australia

I'm sorry but I tried scanning my manual but it didn't want to scan clearly.  The manuals are available from Herb at Lincoln Old Parts, Jack from MarkII Enterprises, or from Books4Cars.com. The manual has an excellent breakdown of the construction and operation of the TreadleVac system.