I need an opinion

[rscurtis]

According to the Monroney label, my '66 Coronet was supposed to come from the factory with the power disc brake option. The fender tag also decodes to that option. According to the article in the August '90 issue of Mopar Action magazine, the car "missed" the option as it was built, and came with manual drum brakes. I would suggest that it came with the PD brakes, but that they were subsequently removed to facilitate valve adjustments and other work on the engine. Since the rear brakes are currently 10 X 2.5", that would also suggest that the car originally came from the factory with the disc brake option. AFAIK, had it originally been a manual brake car, it would have had 11" rear brakes.

Here is the question: Should I change to 11" drums in the rear, find the original PB brake option parts, or leave it alone? It seems to stop fine with the 11's up front and the 10's in the rear.

 

[Roadrunner fan]

If it isn't broke... Don't fix it.

 

[rscurtis]

The reason I'm asking is that there is an ebay seller in Canada who has the complete rear 11" drum setup for this car. It would be an easy way to have all the correct parts without running all over the place trying to find them. I would say that going back to power discs is the least likely option at this time.

 

[terzmo]

but that they were subsequently removed to facilitate valve adjustments and other work on the engine.

Why would they remove brakes to facillitate valve adjustments and other work ? I cannot believe that.

I just pulled the complete rearend out of my 67 R/T...perfect condition..11 inch rear brakes..741 case...391 suregrip..newer green bearings...drum to drum

How did you get 11 inch on the fronts ? Even My R/T has 10's or did untill I went to disc

 

[moparsteve636]

It wouldn't hurt to go to the 11" rear brakes! Depends on correct you want it to be as far as original on weather or not to put the PB disc on!!!

 

[SublimeSixpack]

You say it stops fine the way it is, so why change it?

With that said, personally if it were mine and I was determined to change something about the existing set up I'd convert to disc brakes in the front and leave the rears as they are.

 

[Car Nut]

You say it stops fine the way it is, so why change it?

With that said, personally if it were mine and I was determined to change something about the existing set up I'd convert to disc brakes in the front and leave the rears as they are.

:yes: or switch to all four disc's.

 

[rscurtis]

but that they were subsequently removed to facilitate valve adjustments and other work on the engine.

Why would they remove brakes to facillitate valve adjustments and other work ? I cannot believe that.

I just pulled the complete rearend out of my 67 R/T...perfect condition..11 inch rear brakes..741 case...391 suregrip..newer green bearings...drum to drum

How did you get 11 inch on the fronts ? Even My R/T has 10's or did untill I went to disc

AFAIK, hemi cars were equipped with 11" drums from the factory. When the booster was removed to facilitate valve adjustments, the 11" front drums would have been the logical choice, as the disc brakes are almost worthless without power assist. Since I plan to replace the hydraulic cam with the correct solid lifter unit, it would make sense to not install a booster required with the disc brakes.

 

[mopar 3 B]

The booster for power brakes was removed because the hemi valve cover could not be removed without removal of the booster. Thus 66 hemi cars never came with power brakes and manual brakes would have been 10" x 3".

 

[69Coronetrt]

Here is the question: Should I change to 11" drums in the rear, find the original PB brake option parts, or leave it alone? It seems to stop fine with the 11's up front and the 10's in the rear.

Depends....

How often do you plan on pulling the valve covers?
How often do you plan on stopping?
Do you trust young blondes trying to drive and text?
Do you trust blue hairs that can barely see over the steering wheel?
Do you drive where there are deer or other large animals that appear in the road?
Which do you think your family would prefer?
Since you have the WS and FT showing the PDB, which do you think will help maintain and enhance value of an original Hemi car?
Seems like a pretty easy answer to me.

 

[mopar 3 B]

Good luck with that one. Finding hemi parts that never existed.

- - - Updated - - -

Single pot master cylinder and you want to mix disk and drum brakes that's a good one.

 

[Car Nut]

Single pot master cylinder and you want to mix disk and drum brakes that's a good one.

Why wouldn't a dual master cylinder work?

The booster for power brakes was removed because the hemi valve cover could not be removed without removal of the booster. Thus 66 hemi cars never came with power brakes and manual brakes would have been 10" x 3".

Ok, now this is making since, you'd rather pull the valve cover off more often then stopping the car. Does the Hemi need more adjustments than other engines?

The pictures below shows the booster just move it out of the way.

 

[rscurtis]

Good luck with that one. Finding hemi parts that never existed.

- - - Updated - - -

Single pot master cylinder and you want to mix disk and drum brakes that's a good one.

Did you look at the Monroney label? The car was originally equipped with PD brakes. The fender tag also verifies that. Good point on the single master, but it has been updated to a dual master cylinder.

- - - Updated - - -

Does the Hemi need more adjustments than other engines?




Depending on the engine, yes. Many engines of that era still used mechanical valve lifters, but the hemi required removal of the booster and master cylinder (and opening of the hydraulic system) to remove the LH valve cover.

I asked for an opinion, and I'm certainly getting them! The jury is still out on this, but if the original PD setup became available, it would be tough to resist.

 

[mopar 3 B]

Thought you were trying to keep this original or is there something I do not know about Chrysler master cylinders? 66 and down 1 pot and 67 and up 2 pot. I also have factory info on 67 B-Hemi cars and power disk where not an option. But have seen may things that where not supposed to be and appears yours maybe one of them. Appently engine lift is not a problem with your current setup? And please let us know how the valve cover and brake booster like this combo after you get it to run.