'68 P/B brake booster to '69.. B-body

[44070dart]

I asked at B-body, but no answer. Maybe someone here knows. I have the master cyl. and booster from my '68 Charger, drum brake, that I changed to disc. Could I use this '68 booster on my '69 Coronet that has manual drum brakes. I would buy a new master cylinder or not.

 

[65 Dartman]

I don’t see why not.

 

[YY1]

Does your Coronet already have power brakes?

Boosters and manual master cylinders attach differently.

MC uses studs from inside out pressed into the firewall, booster uses studs the other way, on the booster.

Removing the pressed in studs is a royal PITA.

I destroyed a firewall once, trying to remove the studs from a loaded 68 Valiant with PB.

 

[Professor Fate]

Since they're both B bodies, you don't have to worry about the studs.
If the master cyl. was still good, I'd run it- I've had issues with some new masters.

 

[Dana67Dart]

Parts book says 68-69 use several shared part numbers

IF the 68 master has been modified for Disk / Drum or is specifically for Disck /Drum then that would be an issue on a drum / drum 69 (front circuit residual check valve or lack ther of )

68

69

the reinforcement plate is different manual to power but the same 68 to 69

68

69

 

[YY1]

Since they're both B bodies, you don't have to worry about the studs.
If the master cyl. was still good, I'd run it- I've had issues with some new masters.

Yes, yes you do.

Manual brake cars have studs pressed through two sheet metal firewall sections.

Power brake cars have studs on the booster mount that go into the cowl.

Completely different.

...and if you can get the studs to come out of that sheet metal sandwich without destroying the cowl...you're a better man than I.

 

[Dana67Dart]

Manual brake cars have studs pressed through two sheet metal firewall sections.

Power brake cars have studs on the booster mount.

probably why the reinforcement plate is different power to manual. And I suspect the reinforcement plate is spot welded to the firewall

 

[Professor Fate]

Yes, yes you do.

Manual brake cars have studs pressed through two sheet metal firewall sections.

Power brake cars have studs on the booster mount that go into the cowl.

Completely different.

...and if you can get the studs to come out of that sheet metal sandwich without destroying the cowl...you're a better man than I.

No, you don't.
The difference is not in manual/power brake cars, the difference is in A & B body cars.
A bodies have studs pressed into the brake pedal frame assy, which then comes through the firewall and the master (manual) or booster bracket (power) slides onto those studs and gets attached with nuts.

On B bodies, there are no studs on the pedal bracket assembly. The manual master cylinder has 4 pressed-in studs that go through the firewall and pedal bracket (and reinforcement plate, if present) and attached with nuts from the inside.
For power brake B bodies, the booster uses no bracket and the studs on the booster go directly through the firewall and pedal bracket. The exception would be hemi cars or if you decide to use the A body bracket due to clearance issues.

When a power booster is used on a B body, it will use the A body style master (no studs, or remove the studs from your manual brake master cylinder) in order to bolt to the booster.
The issues start when you try to blend A body and B body parts. But since the OP is talking about switching parts between two different B bodies and NOT an A body/B body swap, it becomes a straight across bolt-in.