Thanks for the tip on Dead Dodge Garage, I have a few shows to watch now. A friend Jason Boeke is involved with Bad Tree Productions on YouTube their stuff revolves around Mopar stuff. Some tech some comedy a really good bunch of guys. They had one episode where they had an OT conversion van on the track with a bunch playing chess on the table that went awry when the van launched. Dan
Jim is correct, it will happen probably even before you drive it. My Fargo and convertible both have single masters. How irresponsible of me. The Barracuda does have a dual master off a ‘68 or ‘69 Barracuda, mostly because it had no master or brake lines when I bought the car.
An easy work-around to use the 10-inch rear drums with the 9-inch fronts, is to put a smaller diam wheel cylinders in the rear. This will reduce the rear brake pressure. So if the stock drum has like 7/8 or 1 inch, look for a 3/4 inch wheel cylinder. This may be sufficient to not need the adjustable proportioning valve. Here's the math: [(7/8)^2 x pi] / 4 = 0.6013 sq in area; and [(3/4)^2 x pi] / 4 = 0.4418 sq in You can see the effective area is .44 vs .60, so the shoes will get approx 74% of the force if using 3/4 wheel cylinders instead of 7/8. For comparison, [1^2 x pi] / 4 = 0.7854 sq in, or if going form 1 inch wheel cylinder to 3/4 the reduction is about 56%.
Thanks I like your idea, simple! One question I have is can I order a wheel cylinder with a different dia and maintain the same mounting bolt pattern? Or do I simply (maybe) modify the mounting? Dan
It may take some searching and a helpful auto parts store person to allow opening boxes, but you can likely find smaller diam wheel cylinders with the same mounting bolt spacing and hose connection. Such as maybe off a Ranger truck, or maybe even small car.
Swapping wheel cylinder diameter to make up for the difference in drum size could bring in a whole new level of complication, especially if the exchange will be for a short term. Swapping a directly interchanging, bolt in, smaller diameter wheel cylinder may be an option, but I would approach any backing plate modification with much caution. Personally, I would convert to front disc brakes, change the master (for simplicity) and add an adjustable proportional valve, rather then mess with different rear wheel cylinders, unless the mismatched front and rear drum brakes are the final destination.
I agree adjustable proportioning valve, it is way to go, I haven’t got mine plumbed in the Fairlane yet but when I do I will be able to adjust it from the driver’s seat. Not only does it help with brake sizing but tire size front to rear also.
The easy way to change to dual master is to use 67 to 72 master cylinder. Same mounting point as the old one.
Let’s say you want to stay with the original master cylinder, you could search for the optional 10” front drums
I drove a ‘65 valiant with a single master cylinder and 9” drums on the front, 10” drums on the rear in the mountains and city and didn’t die, don’t over complicate things, put the car together and drive it. Remember the front does way more braking than the rear. No wonder so many cars don’t get finished.
Next I installed the new gas tank and sending unit. The sending unit/ pickup I ordered is 3/8 ,only need 5/16 so I reduced to 5/16 at the pick up, I’ll have the 3/8 capability if I ever need it. wire brushed and applied Ospho in the tank area the applied POR15. I also plumbed in a 3/16 return line. Dan
At present my plan for brakes is to install the 8.8 rear with the 10” drum plumb up, test drive and go from there. If the little Dart stops good I’ll be done if not I’ll move along with who knows what, disks, dual reservoir MC prop valve???? I really appreciate everyone’s input. Lots of ideas if needed. Dan
Thinking about this thread had me remember my mom learning to drive on a 63-66? Valiant or Dart IIRC. It was manual with a column shift. Did such a thing exist?
Yes, there were push ****on autos, column shift autos. floor shift autos. There were column shift manuals and floor shift manuals.
My first car was a '66 Valiant 100, 170 c.i. slant six, three on the tree. Dude wanted $100 for the car. I offered $75. We split the difference - $87.50 brought it home. Put 15K miles on it in a year in a half, sold it for $125. It almost burned more oil than gas, always a fresh set of plugs, ready to go, in the trunk, for when the sparkers got oil-fouled...
Mine was a slant 6 column shift auto no way was I going to make it work with the linkage I have. It’s now floor shifted. I always like the push ****on shift for their uniqueness. Dan
Good enough is often good enough. But, at the same time, having knowledge of what can make good enough not good enough is good to know. Finding such things out as a total surprise is usually not a good experience, and can sometimes be tragic. I do not buy into the concept that some things that are good enough fail all the time, and I'm not going to repeat some else's hear say. Having had personally experiences of several of those times when good enough was not, I feel obligated to advise people about what I have experienced. Do with that information what ever you choose, but at least one possible trouble spot is placed in their memory. Slightly bigger rear brakes often don't cause a problem under normal driving conditions, but a bit of wet pavement, and a quick need to stop can change everything. I'm going to continue pointing the things I have personally experienced out. If someone got hurt because I did not speak up, is not something I'm willing to live with.
The Jalopy Journal
