Master Cylinder Compatibility, OEM Bendix

[1970FuryConv]

1970 Fury Convertible, front disc, rear drum. 1970 power brake booster
Everything is factory stock except I put a Rick Ehrenberg aluminum master cylinder on it that leaks from the caps, despite 2 different caps and seals tried.
(I know about Dorman 42044 and 42081. Caps & Seals)
My question is about factory master cylinders and what is compatible with 1970 Power Brake Booster
From an article in Mopar Action 2005
C-Body Disc/Drum Brake Master Cylinders, by Bendix Casting Number (Per the article, Bendix in the only manufacturer Chrysler used for our master cylinders)
1967-1969 are same
1970 is one year only
1971-1975 are same
Are all of these compatible with 1970 Booster and Push Rod? If not, which are compatible?
Thanks

 

[413]

You have a drum booster. How does it work right with that adapter in there?

 

[CBODY67]

That master cylinder looks like what is on my '80 Newport OEM power disc/drum system. It ALSO looks like what Mopar Perf sold as a "P-number" lightweight performance upgrade master cyl. Never had any issues with the one on my '80. FWIW

Have you checked the internal differences (as in piston diameters) of the various disc/drum master cylinders? Then, are the pushrods more universal than not? What about the rear drum brake wheel cyl diameters?

Just curious,
CBODY67

 

[1970FuryConv]

You have a drum booster. How does it work right with that adapter in there?

The booster came off a 1970 Sport Fury with front disc/rear drum. I guessed it was for a power disc brake set up. Could it be that booster not powerful enough to properly actuate disc brakes?
I measured the piston depth from the rear mounting surface of the master cylinder. Then I set up the push rod so that it was slightly less extension forward of the front of the booster.
The brakes feel sloppy at first then as I push further they firmly engage and stop the car.

That master cylinder looks like what is on my '80 Newport OEM power disc/drum system. It ALSO looks like what Mopar Perf sold as a "P-number" lightweight performance upgrade master cyl. Never had any issues with the one on my '80. FWIW

Have you checked the internal differences (as in piston diameters) of the various disc/drum master cylinders? Then, are the pushrods more universal than not? What about the rear drum brake wheel cyl diameters?

Just curious,
CBODY67

Have you checked the internal differences (as in piston diameters) of the various disc/drum master cylinders? I can check shop manuals. 1970 FSM MC bore 1". 1971 FSM MC bore 1 1/32". (I went with this aluminum one because Rick Ehrenberg directly said it would work on my Fury and the Aluminum eleinates rust as an issue. I do not know the bore.)
Then, are the pushrods more universal than not? Push rods have adjustable length. Stud below threads in/out of female end of push rod. (Wire wheeled before reinstall)

What about the rear drum brake wheel cyl diameters? Original wheel cylinder were 3461776, OEM, but pitted. Purchased NAPA United 37235 wheel cylinders both sides. Bore diameter .9375". I did not measure to assure same bore as 3461776.

 

[CBODY67]

For reference, I did my research (just not) via the Raybestos online catalog, via RockAuto.

-- No Raybestos master cyl for front disc brakes listed for 1967 or 1968 model years. 1967 and 1968 showed different wheel cyl kits and whl cyl part numbers. Appears to be .844" piston dia.
-- Frt drum brake master cylinders were the same 1967-1970 A-B-C-E 1.00" bore
-- Frt disc brake master cyl 1969-1970 B-C-E 1.125" bore
-- Frt disc brake master cyl 1968 C 1.125" bore (from the Dynamic Friction catalog)
-- Frt disc brake master cyl 1971-1973 C-E, 1971-1975 B 1.031" bore .844" piston dia
-- Frt disc brake master cyl 1974-1978 C 1.031" bore .844" piston dia
-- Frt disc brake master cyl 1980 Newport 1.031" bore .844" piston dia

From my investigations:
---it appears the rear why cyl bore remained at .844" for many model years and platforms, main one being the C-body cars.
---It appears the master cyl bore, 4-piston and single piston front disc brakes began as 1.125" bore diameter on C-body cars. Then decreased to 1.031" for model year 1971 and later, into the end of 1981 R-car production. Full-size pickups were similar. Which means the later aluminum master cyl will retrofit to vehicles into the earliest 1970 vehicles.
---Each master cyl would need the pushrod adjusted to match it, per factory specs.

I would have suspected the C-body Budd caliper pistons would need more fluid than the later single-piston models, but that might not really be the case? Or might the volume difference be compensated for in the valving and such of the "proportioning" and "metering" valves?

In any event, there seems to be more commonality among the platforms and brake components that initially suspected. In my catalog look-ups, I used "Chrysler New Yorker" for the particular model years, for consistency.

Just what I found. Not sure how that relates to what is in the Genuine Chrysler Parts Manuals.

Enjoy!
CBODY67

 

[1970FuryConv]

For reference, I did my research (just not) via the Raybestos online catalog, via RockAuto.

-- No Raybestos master cyl for front disc brakes listed for 1967 or 1968 model years. 1967 and 1968 showed different wheel cyl kits and whl cyl part numbers. Appears to be .844" piston dia.
-- Frt drum brake master cylinders were the same 1967-1970 A-B-C-E 1.00" bore
-- Frt disc brake master cyl 1969-1970 B-C-E 1.125" bore
-- Frt disc brake master cyl 1968 C 1.125" bore (from the Dynamic Friction catalog)
-- Frt disc brake master cyl 1971-1973 C-E, 1971-1975 B 1.031" bore .844" piston dia
-- Frt disc brake master cyl 1974-1978 C 1.031" bore .844" piston dia
-- Frt disc brake master cyl 1980 Newport 1.031" bore .844" piston dia

From my investigations:
---it appears the rear why cyl bore remained at .844" for many model years and platforms, main one being the C-body cars.
---It appears the master cyl bore, 4-piston and single piston front disc brakes began as 1.125" bore diameter on C-body cars. Then decreased to 1.031" for model year 1971 and later, into the end of 1981 R-car production. Full-size pickups were similar. Which means the later aluminum master cyl will retrofit to vehicles into the earliest 1970 vehicles.
---Each master cyl would need the pushrod adjusted to match it, per factory specs.

I would have suspected the C-body Budd caliper pistons would need more fluid than the later single-piston models, but that might not really be the case? Or might the volume difference be compensated for in the valving and such of the "proportioning" and "metering" valves?

In any event, there seems to be more commonality among the platforms and brake components that initially suspected. In my catalog look-ups, I used "Chrysler New Yorker" for the particular model years, for consistency.

Just what I found. Not sure how that relates to what is in the Genuine Chrysler Parts Manuals.

Enjoy!
CBODY67

Hi Willis,
Thanks for all your hard work!
Per Mopar Action, Bendix is the original manufacturer for all drum and disc master cylinsders 1967-1975 passenger car.
Casting #2225621 is 1 1/8" bore for 1970 C-Body disc brake and 1967-1969 B-body disc brake. 1970 C-body is one-year only for that master.
Basically, I need that casting number to be sure it's right for my booster.
In addition, White Post Restoratoins charges $245 to rebuild a master cylinder.
I have a disc brake booster core (not on car). White Post Charges $445 to rebuild that.
Converting back to stock is getting pricey fast. Ben