Seemed too good to be true, but tried to use a booster brake set up as above and doesn't seem to be possible. The bolt centers are different . Mounting plate would have to be extensively modified. My brake pedal rod is much longer and larger. Also looks like my power steering /box plumbing is in the way. Has anyone else noticed these problems?? Should I regroup and go with a stock booster. It looks like my brake linkage has the hardware to hookup a stock unit. Where did the ?misconception come from to use the duster booster or might I have gotten the wrong one from the parts supplier??
Steve, I have read many a tech comment on the Forward Look web site pages and also here in the 59SF forum and was wondering myself on this subject what to use.
Most say they do this with little modification, but what is little and what is a lot and what did people actually do to make all of the A body booster / MC work.
I also want to know but can't answer your questions, right now I am just going to put on the A body low profile MC with a Proportioning device using my old Power Bellows unit. I might have to get a Mopar performance adjustable push rod to make all of this work.
Roger or John F. any suggestions mfor Steve and I ?
The 1975 A Body non-power master cylinder is a good disc brake changeover to use in a non-power system. I have not heard about using the booster, There are other boosters but all require a complete changeover.
In addition you will need the proportioning manifold adjustable rear brake hold off valve and lines, and plumb them to your brake system.
The low profile mastercylinders of the late 60's nd early 70's work with our exhisting boosters of the late 50's and early 60-61. these require the removal of the residual check valve in the front brake outlet of the cylinder. or your disc pads drag all of the time. you will need to have the proportioning system as well.
I realize there are many ways to skin a cat! Make sure to do your research, the life/lives you save might not even be you and yours.
Rick, would you recommend upgrading to a newer proportioning device (maybe one from the same car as the MC is from) or using the original 59 one and put a Mopar adjustable proportioning device in line with the rears?
I know there has been numerous threads on this but wanted to hear from a 30+ year mechanic...
John,
I wisely leave any conversion ideas and plans in the hands of more worldly people...Rickymopar seems especially knowledgeable in all manner of Mopar Modifications! He will get to the bottom of this.
I went the factory route, risking my car and life with the original brake set-up.
I put front disc brakes on my '59 in 2005. Used AAJ basic kit and bought rest of parts from local parts stores.
Dug out my folder and according to my records I purchased and installed a 1975 Plymouth Duster power brake booster with master cylinder. Bought it from Auto Zone for $120 (includes $20 core charge). Part # is 50-6101. Checked their web site and they are still available, now for $128.
This unit bolted up perfectly to my firewall with no modifications that I remember. I played with the adjusting rod inside master cylinder but that was it.
I mounted a button type brake lite switch on steering column. Proportioning valve I think I got from a Volare or Duster parts car from that era.
Fins-I'll try to take a few pictures of my situation. Thats weird that your booster would bolt up. My firewall is stepped between lower bolts and upper bolts. Bolt center were about 1/4" off. My mounts are pressed in bolts which are part of the brake pedal pivot assembly, instead of receiving holes for the 4 booster mounting bolts. My car never had power brakes. Might that be the problem???
Here are a few pictures that depict my problem. I've kind of decided to try manual disc brakes. If that doesn't get it I'm thinking to try a stock booster.
shows stepped plate removed from firewallfirewall w/mounting boltsduster booster and my 59 mc
Roger, I might have to go your way to keep it basic and functioning, but since I will eventually tow a trailer with this car, I would like to switch to disc's. I could have bought the AAJ kit, but always trying to keep the costs down and I have done other conversions to my Cuda and Charger that went great.
I bought a set of spindles off a guy on ebay two years ago that were M or J body spindles that he (seller) would work on late 50's mopars. And then I bought locally a set of rotors to go on the spindles. atill need calipers yet.
Now, my car was a power brake, bellows type of car (like yours Roger) I was told to put the A body non power brake MC where the old single pot MC went, And leqave the PB Booster above. But Fins59 car was already a manual MC car ( ibeleive from the pictures and it sounds like Steve's car was also a non power car. So that would make sense to have booster and MC combo in place of a Single Pot MC. But with the PB above in a different plane....
I can't do that since it would leave a gapping hole where the old bellows use to go. The Guys on the FL site (great site too! I went to it cause Roger keeps referencing it in his posts) It seems that a A body non power MC used in the same place as the old Single Pot MC will allow me to keep the original Power booster above , and only make the exception of the non-correct MC. Not a big deal since I have taken some liberties with my 59, not much, but some.
I have read Stefan's conversion (DBC II) and he kept the original Power brake set up and put the two chamber MC pot below it. He did re do the proportioning device in his 59, The MC set up was a non-power A body type but since it is mounted seperately from the booster it works, just need to balance the rear and the fronts with the proportioning device.
Does any of this makes sense? Ricky Mopar lives about 15 mins away from me in the next town. I think I will wisk him away some day when I am closer to doing this on my car. That is when my arm gets out of its sling (rotator cuff surgery).
Steve, sorry to bust in on your thread. Hopefully we can all figure it out soon.
OK There is an A Body booster and bracketry much like the 426 hemi booster and master cylinder standoff that very well might be a direct bolt on. I have a new old stock one here that I was going to use to convert my Challenger to power disc brakes. I am still deciding, The Challenger stops great with the manual disc system. John, If you want...You can check this out being your car is still partially dissassembled. We can take pictures so people will know what it looks like!
Now continued brake info.We need to discuss the hydralic safety system and the hydraulic system safety switch and the pressure metering valve I.E. proportioning valve. I really love the early systems with their beautiful brass machine finished parts. They also seem to last a really long time if you occationally bleed out your brake system. D.O.T.3 brake fluid is hygroscopic and absorbs moisture that will later cause internal hydraulic brake parts corrosion, and then failure.The simple and my favorite is the mid 1970's self contained units found on C, R and W full sized body styles. of course in the brass. and contain both the safety switch and the pressure metering. The cast iron units are fine.. They just don't look as nice so hide them. you can add a hidden light in your gauges to let you know of a leakage problem. Thus the safety switch is really nice to have. These turn the light on if there is leakage causing a difference between front and rear brakes. I have only used D.O.T. 3 brake fluid, I also realize D.O.T.4 and 5 exhist.Just haven't found any manufacturers using them. They might be fine for our old cars. I really don't want to be the one to find out the hard way, I'll just continue to bleed my brakes yearly.
I have the Parts Book open in front of me, and for what it's worth, ALL '59 Plymouths had stepped firewalls and all had stepped "reinforcement"s..(the name they gave to the mounting plate). Further than this I cannot advise...I don't know what a Duster master cylinder looks like, etc etc.
Not a problem, being reinforced is a really good thing. Will post pictures of the booster standoff bracket. There are already some great pictures of one solution in the showcase. Page 3. of the Sport fury section, presented by Stefan Steinmaier of Portugal. I have done this same style of conversion for many years, mainly for the safety reasons. Even if your old bellows booster fails you will have good manual brakes! Better than adding the A body booster.
I'm kind of developing a theory about how the 75 duster misconception may have originated, if it is a misconception, as it appears. Roger at AAJ Brakes was dubious at best about my pig headedness regarding the Duster idea, so he sent me a picture of an offset booster, which i think is the next generation of MOPAR booster brackets , probably 1965 vintage vs 1975. These appear to be available on Ebay as a unit with mc and booster. I can see how they could easily be modified or utilized. However, I have a deathly fear of the need to work under and around my dash-so the bolt on idea was a no-brainer for me!! So thats how I got started down the old "Duster Road". Roger's picture is attached.
Roger's {from AAJ Brakes} suggested approach
So of course the moral of this tale of woe is to heed the experts!!
That's the ticket, just what the doctor ordered.Great picture!These were optional on all A Bodies... not just Dusters. there is also a side brace to help stabilize the whole thing that attaches at a right angle at the master cylinder bolts to the fender well.
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