The Polara Disc/Drum brake Conversion begins

[mr. fix it]

Wow those parts cleaned up nice!!
Did you dilute the AM at all?
How long did it soak?

Sorry for the delay in responding.

I dilute it 50/50 pouring AM into the water not the other way around... (it's important to do that.)

For full affect I usually dip it for about 4 hours then gently scrub the heavy rust still on the part.

I then let it soak up to 24 hours depending on the thickness of the metal.
I tape up the parts i don't want etched or stripped.

Very important step is after the acid Magic that I neutralize the part with water and a good dose of laundry soda(Baking Soda)
Walmart sells it pretty cheap in the laundry section

 

[mr. fix it]

Here is one of the backing plates soaked and cleaned with AM
It created a really interesting film in the tub I used.
the backing plate is still in the tub...

 

[mr. fix it]

Before and after shots of the backing plates & hardware

 

[mr. fix it]

I was lucky that when I bought the car back in 2013 there was an NOS disc brake C body dual M/C for disc brakes with the car.
The brake lines from the Newport were in most excellent condition and cleaned up very well along with the OEM Newport distribution block
I only had to remake one front brake line

 

[mr. fix it]

I also had thought about reusing the Booster from the 73 but quickly saw because of the shift linkage as mentioned in numerous threads that it can't be used.

 

[mr. fix it]

Edit function not working right now.

I wanted to mention that even though the AM turned black, it is still important that it doesn't get on you cause it will continue to work for some time.

Once you want to dispose of it.
mix up a bucket of Laundry soda and water and slowly pour the AM mud into the soda water to neutralize it so you an dispose of it safely.

 

[mr. fix it]

I tackled the rear brakes on my own tonight. nothing special really, remove the brake line, remove the e-brake cable and then pop the axle out after removing the retaining nuts of course!

Reverse the process adding the 2 1/2" pre-assembled backing plates .
Torque to spec, adjust the shoes to the drums, bleed brakes and it's ready for atest run..

Too bad we are getting 6" of snow tomorrow!!

 

[65sporty]

Thanks for the detailed pic's, great swap, it should make a huge difference in the cars braking ability

 

[mr. fix it]

I sure hope so and expect that it will.
I've had a few people warning me about the drum booster setup and plan to do my own testing to determine if it is not powerful enough.

There are drivers on both sides of this fence.

I'll be sure to make a comment once I have tested the car.

I always felt the drums brakes were marginal at best yet some here and local Mopar guys insist there is nothing wrong with drum brakes even without power boost.

 

[mr. fix it]

So an update. Back brakes are done but having a heck of a time bleeding the brakes with the stock 73 distribution/proportioning valve.

I found the technique on how to do it but I decided not to chance the NOS M/C I have and ordered a new 73 M/C.
It shows a special tool to keep the valve in place while bleeding the brakes...

Once that arrives then I'll move forward to bleed the brakes again.

 

[mr. fix it]

Currently I have a ton of front brakes but no rears or very little..

 

[mr. fix it]

Update on the brakes here.
I ended up tossing out the NOS Master Cylinder and went with a 73 M/C as a lets's be sure factor.

I suspected the OEM distribution block/proportioning valve was stuck or tripped.
I hooked up my test light to the grounding pin and sure enough it lit up.
Definitely an indication that the system is not bled totally yet or the block is stuck.

I had my lovely wife assist me with bleeding the brakes again.
I let the front caliper loose and bled the rears.
Re-bled the fronts after the rears
Light was still on so I cautiously pumped the brake pedal then viola! the light she went out!
I have brakes on all 4 corners now and just have to wait for a dry sunny day for the test drive!

Will check for residual leaks and re-bleed since I am using silicone Dot5 fluid after a 24 hour waiting period to make sure all air is gone.

I'm hoping I can put this the done column!

 

[mr. fix it]

I tried to get the wheels back from the Seneca but it refused to let me since it has attitude now with the 5 on 5's and the RWL's

 

[mr. fix it]

Ok so update on the conversion.
I finally has the strength and duration to install the longer front wheel suds and spacers.

All is good now.
Lots of threads to hold the fronts on and the rims are spaced out enough to clear and spin freely.

I torqued the wheels on and down on the ground and took Trixie out for a test drive.

Having the new brakes on all fours will take time to break in but so far I am happy with the results.
I checked the rotor/hub temps with a pyrometer and both were at 105f' after the test drive
the pedal feels like it takes strong affect about half way through the pedal travel but this did this with the drum brakes as well.
Nice and steady braking, no grabbing anymore plus the vibration that has haunted me since buying the car is virtually gone.
I suspect it was a brake or slightly bent spindle issue...
I did find a leaky WC when I pulled the drums off the front which didn't help...

 

[mr. fix it]

And finally, I used a 5/16" wheel spacer to give me enough clearance to bolt up the wheels since I have the aluminum Cordoba rims.

Used a universal spacer
Moroso 710-46480 Stud/nut kit from Jegs.com

 

[Zymurgy]

Nice, glad that worked for you. Now the big question is the salt off the roads so you can test drive it?

 

[mr. fix it]

Nice, glad that worked for you. Now the big question is the salt off the roads so you can test drive it?

Yes, I did Mike. we had a bunch of rain recently and I was able to get out this after noon for about 15 minutes of city driving.

The rotor temps were at 105f' each after the test drive.
No pulling, just felt a bit spongy.
Had the same feeling with the drum setup.
i may need to re-bleed the brakes but will let it go for now.

i really need to be able to let the brakes seat in before anymore tinkering with it.

 

[Zymurgy]

I had issues bleeding mine lines, but finally got all the air out and have excellent peddle feel. I was amazed out how tough the rotors where, with all the issues I had and the several times they were so hot that they were smoking, they never warped.

I rained here all week so our roads are salt free too, hopefully I might get Goldie out for a run this weekend. I started her up and moved her a couple of weeks ago, so I could spray in my shop, but the roads were covered in salt at the time.

 

[mr. fix it]

Thread update
I have about 500 miles on the new brake setup and I am very pleasantly pleased that the brakes are setting in and even with the drum brake booster it is a good pedal feel and average effort to stop the 2+ ton barge
If I felt up to the task I would install a dual diaphragm booster to test how much difference it makes as suggested.
With the stopping power as of right now I am feeling secure in the brake system
I have locked the wheels up with an extra push of the pedal and have no nagging feeling that I need to add the dual booster right away

I hope the thread has helped others in their quest for better brakes anyone with questions should feel free to ask

 

[Zymurgy]

If you are down in my neck of the woods again, you can take Goldie for a spin for comparison. Glad you are happy with the conversion.