1965 Valiant disc brake upgrade

The Proper Brake Distribution/Proportioning valve question: Which value should I use for my conversion? I followed the advice of 57dodged100 and did some research based upon his thread.

I went to InLineTube website and it said the following… “The first year for disc brakes on GM and Chrysler products was 1967, Ford was 1966. All American cars built prior to this had four wheel drum brakes. Disc brakes were introduced as an option from 1967-1972. Starting in the 1973 model year, front disc brakes were primarily standard and front drums were rarely available. The dual master cylinder that separates the front and rear braking systems was introduced and standard on all cars in 1967. Therefore, all 1967 and newer cars came with dual master cylinders from the factory. Disc brakes require over three times the line pressure of drums, so the master was divided to provide pressure to the front and rear separately. This also meant that if a front line blew out the car would still have pressure to the rear brakes and vice versa…. In 1971 for GM and 1972 for Chrysler, the one-piece combination (distribution/proportioning) valve replaced the multiple piece design. The combination valve keeps front and rear systems separate, splits the left and right front lines, houses the sending unit for the brake failure warning light and provides the proper brake line pressure for the front disc and rear drum systems. This is why it is important to know what is correct for your car and how your car can (or will) be converted from drum to disc. There are three basic disc conversions for 1967-70 cars: 1) Factory original conversion, 2) Combination valve conversion and 3) Adjustable valve conversion. Each conversion has its benefits.”

My car is a 1965 so disc brakes were not available. I don’t want to covert to a two-piece value design found in 1967-70 A-bodies, thus I need to move to later model combination valve. I also only have a single brake line running to the rear. With the combination valve conversion, one end attaches to my original single rear brake line, and I will only need to plumb two new lines to my new Master Cylinder.

The #BLK250 is described on inlinetube.com website as a “1969-74 A-body Distribution Block - Dart / Duster / Demon. For use on 1969-74 A-body Mopar with drum or disc brake. This is the distribution block that is mounted below the master cylinder which feeds fluid to all four wheels.”

I also found a different Proportioning Value, RSD-PV12, that Mancini Racing website says was original equipment on A-bodies with disc/drum and single brake line to the rear. (“1971 1974 Chrysler, Dodge, Plymouth A Body - Barracuda, Dart, Duster, Valiant & 1969 1970 Chrysler, Dodge, Plymouth B Body - Charger, Coronet, GTX, Road Runner”) (source: ManciniRacing Part number RSD-PV12).

With either I am looking a $90 dollars for these gems, unless I buy a used one and rebuild… I’m not going the rebuild. In either case I need to run two new lines from the Master Cylinder. I am not sure where my brake failure light/censor is on the 1965 valiant. You can see from the pic that it doesn’t connect to the original distribution block. I may not even have one? I don’t think it matters if I connect it or not… may be a project for the future.

The Push rod Question: Can I simply reuse the pushrod that is attached to my original Master Cylinder (Bendix 11096) which has an intergraded pushrod? Do I need another part or adaptor to use the newer Raybestos MC36406? According to Disc-O-Tech article I can just reuse the pushrod. (see attached or see http://www.moparaction.com/tech/archive/disc-main.html) I am going to do some double checking on this…

The Master Cylinder Question: Which should I use? I decided to use the Raybestos Master cylinder (#MC36406). Thanks again 57dodged100 for the advice.