Brake Booster has two studs - Master cylinder has 4 holes

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69cudaownr

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I have found that my brake booster has two studs for the master cylinder to mount to it. The new master cylinder has four holes to be mounted. I have triple checked the new master cyl. part number for my 69 Barracuda and it seems to be correct. So now I am guessing my brake booster is wrong for the car.
Do I have a different year brake booster on the car?
Any info will help.
Thanks
 
#1 reference material to have for any Mopar is the correct FSM (Factory Service Manual) for your car. It will save you many headaches and much torture.
 
Sounds like you have a GM or Ford booster. You can buy adapters.
 
I would just roll with a more modern, lighter, better sealing, non rusting, 2 hole aluminum master cylinder. Of course you'll have to figure out what brake booster you're working with first. Pictures would be good.
 
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Vans, F Bodies
speed-mopar-style-1-1-8-inch-master-cylinder-with-black-plastic-reservoir-3.jpg
 
You have a good problem since most people go the other way, using a 2-to-4 bolt adapter plate to use a modern 2 bolt aluminum master cylinder. The old 4-bolt cast-iron MC's rust to ugliness and the flat lids with poor gaskets slosh out fluid to de-paint your firewall (more rust) and let moisture get absorbed into the glycol brake fluid. Your booster looks kind of vintage 1970's when GM and Ford already used 2-bolt MC's (I think). The V-band makes it appear a Midland-Ross type. But, it could be one of the newer Mopar booster kits on ebay which have the Mopar firewall bracket-lever but use a GM booster and cast-iron MC, though they come as gold chromate but some prior owner may love black.

Many here like the 1980's Mopar truck MC, which looks like post 5, but maybe one from GM-world would be less risk. Your booster appears to have an adjustable tip, which helps. Adjust the tip so it just barely touches the MC piston as you bolt it up, so no play but doesn't push in the piston to cover the inlet port. My 1965 Dart (in avatar) has a late 1990's MC for a Breeze w/ ABS on an Intrepid booster. Before that, insure the brake switch is not preventing the pedal from fully retracting. It should just sense the pedal motion, not halt it, and yes its bracket is adjustable. That seems to be a common mistake.

You want an MC before ~2000 when most changed to bubble-flares, and insure the ports match the fittings on your brake tubes. Note that even with 1/8" tubing, Mopar usually had different size tube nuts at the MC so that the front and rear circuits weren't mixed up. Your tubes don't appear factory, since those were usually were formed in a loop at the MC, at least in later cars. If needed, you can cut off the ends to install a different tube nut and form new double-flares with a tool (you'll find it ever useful). Insure the rear tube goes to the front brakes and front tube to the rears. If you have front disks and rear drums, you'll need a proportioning valve.
 
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Thanks for the info. The master cylinder I removed was a four bolt that actually had been drilled with two more holes centered to fit the booster instead of using an adapter.
 
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