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Mike,
I've seen that chart before but don't know where it came from. It may have some errors. Here's what I found for Master Cylinder bores from Chrysler factory info (which may have errors too, but at least its from a good primary source).

The chart you posted indicates 1968-69 B-bodies used master cylinder p/n 2883058.
Chrysler's Master Technician Booklet from 1969 agrees, (Master Cylinders for 1969 model year)

However the Plymouth 1968 Service Manual shows the following specifications.
All models with Drums 1"
Kelsey Hayes equiped 1"
Bendix equiped 1"
Budd equiped 1 1/8"

That noted, the Master Technician's booklet from '67 states the Bendix equiped cars have master cylinders with 1-1/8" bores. page 13, Master Cyliner Information Are they both right? Is one wrong? Maybe, I don't know. Probably some more digging, and searching with the restoration crew would be needed.


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These are often called the "Texas" valve for obvious reasons. They are the ones I mentioned from a 73-76 A body.


Frank - wrong link/picture. Those are later combo valves. The Texas shaped valves look much more like the state! :LOL:

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I know a combination valve is in order but will that fix the feel of the brakes?


It will not fix the problem you describe. Get whatever E-berg recommended. If he recommended a proportioning valve, then just get one and plumb it into the rear line. A proportioning valve reduces the increase in hydraulic pressure to the rear wheel cylinders once the system pressure reaches a set point. For example, if the set point is 300 psi, then from 0 to 300 psi all four brakes receive the same hydraulic pressure. On a harder stop from higher speed, lets say you apply more force on the brake pedal, and the pressure from the master cylinder produced is 400 psi. If the proportioning valve is set up for 50% reduction, the front brakes will get 400 psi and the rear wheel cylinders will see only 350 psi.

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I guess I need a residual pressure valve in the rear lines as well - will that fix the pedal height?

Many master cylinders come with a the residual valve on the front port (for the rear brakes). If there is no residual valve, the springs on the shoes will squeeze alot of the fluid out of the wheel cylinderss and back into the master's resevoir.

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Brakes are bled I guess - no spongy but low and hard as hell pedal.


Read MTSC booklets on brakes to see Chrysler's recommendations on bleeding. Gravity was Chrysler's prefered method for the front discs. If you hae any doubts get a helper and do the drums with the pump shut method, and make sure the bleeders are open at least a half turn.

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Brakes just suck - low but hard pedal and I gotta stand on it to stop the car..



As others have said, could be a number of things. Troubleshoot possible faults before changing parts. A few points that may be helpful
* Recognize that duo-servo drum brakes are self energizing. They require less pedal effort than equivalent disks (unless the lining's overheat and lose friction which doesn't happen in everyday driving).
* Lining material can make a difference. Some linings have more initial bite than others. Some of the modern high performance oriented linings may say 'street' but don't really bite until warmed up. Also, many of the newer high performance linings require bedding in that transfers material from the pad to the disk (or drum). This is what AndyF was talking about. On old school and some current organic and semi-metalic linings this is not really an issue, but on many of the new performance linings, it is. Finally, any grease, oil, etc, will mess up a lining quick! Brake cleaner is your friend!
* Final thought, make sure the rear drums are adjusted properly - just a few clicks shy of dragging. At lower speeds they a contribute a lot and will effect the initial pedal feel for sure.