Drum to Disc conversion MP Brakes Legend Series Kit on 66 300

[Frank Odenthal]

So I will Open a new thread to Share some Information and pics on my front drum to disc conversion with a MP Brake Kit. The desicion for this particular Kit was taken 2 years ago.
I was planing a front end rebuild and already had collected all required Parts. I thought that would be the right Time to make the disc swap as well.
A friend of mine moved from Detroit area to Germany and he offered to me to Transport the kit in his container along with his old 57 Ford.
I wanted to keep my drum spindels because I thougt it would may be difficult to get some 73 disc spindels and the mating discs and calipers and so on..... A complete kit to use on my drum spindels including all required Parts sounds most reasonabel to me back then.
Possibly I would make it different today, if I would neeed to make once again.

So why MP brakes ?
They offered a complete Kit for 65 to 69 C-Body for a good price.
I was struggling with SSBC, because I read many comments about high pedal forces and people went with hydraulic assist to overcome this issue.
RAM MAN was not known to me that time.

I started the conversion in Februar 2018. It was cold outside and inside my narrow garage as well.

 

[Frank Odenthal]

My 66‘ 300 came with OE power booster 4 wheel drums and a single brake cuircuit.

The MP Brake Legend Series Kit came with 11“ x 1“ rotors, billet Aluminium hubs, single piston cast iron calipers, all bearings, brake hose and laser cutted steel adapter plates as well as a dual master cylinder and a universal combination valve. This two last parts were not shown in the kit below (special order)

Master Power Brakes

It did not include a new power booster.
I purchased a Bendix style dual Phragma booster at the local Moparshop.de.
I think it is a B body booster, but it supply’s the needed power and fits to the firewall and to the master brake cylinder.
The brake pedal needed an update to fit to the shorter booster push rod.
I will come to this later.

Everything starts with the disassembly. As I want to spend a new frontend Kit with new lower and upper ball joints and bushings, everything comes out.

1. raise the car on jack stands, remove the wheels.

2. thing was breaking loose the upper ball joints just a few turns while still on the car. I takes a 4 feet tube enlargement to apply the right amount of torque. You will not want to make that on the bench.

3. release all the tension from the torsion bars.

4. remove upper control arm in a unit with lower control arm and brake from the car.

 

[Frank Odenthal]

With the complete unit on the bench it is much easier to separate the lower and upper tapered ball joint studs from the spindels. The upper once came out easily with a simple separator tool as shown here in the forum several times. The lower ball joint stud was so thighs,that I need to buy a new solid tool to remove it. it looks similar to the tool shown in the Shop manual and is very solid and provides maximum separation force.
1. did not work.
2. works easy.

 

[Frank Odenthal]

Whith all the ball joints separated, the components were cleaned up for later sand blasting and painting.
The brake drum was removed to disassemble the brake anchor plate from the Spindel.
Spindel was also cleaned up, checked and painted.

Besides the brake conversion, all the bushings were removed from the control armes and replaced. this is a different story, which was told here in the past already.

MP brakes did not provide any directions on how to place the adapter plates and where to locate the calipers. In the front of the Spindel or behind ?
I made some trials, just to check what setup will provide the best brake hose routing to avoid any interference issues later in any driving condition ( jounce, rebound, full turn to left and right in this conditions).
My result was the best way would be to set the calipers behind the spindels. That would provide the best breake hose routing in a similar way as with the drum brakes.

One MP brake manufacturing issue observed during this operation was the precision of the cnc laser cut of the adapter plates.
Only one of the smaller screws did fit. The bolt pattern did not match the Spindels regardless which way I tried to assemble.
It was required to drill larger size holes for the small bolts. My concern was that this can cause brake pad misalignment later, but it was my only chance to bolt the parts together.

 

[Davea Lux]

This is a case study in why a lot of us prefer to use stock components for the disc conversion. I would be worried about the plate adapter working on the bolts as the holes should be the same size as the bolts to prevent any movement. Keep in mind that there is a tremendous amount of torque on all the brake components on a hard stop, anything that can move will move and in time this could fracture the mounting bolts for the plate. My 2 cents worth.

Dave

 

[Darby]

I like the disc brake conversion you're using. It's a lot like the one I purchased from
Engineered Components Incorporated

ECI Disc Brake Conversion Kits - Chrysler Products

I went with the 13" cross drilled Corvette rotors for the front and rear. It's been a couple years since I purchased them, but I think it was less than $1800 for everything including the master cylinder. I took the brackets and rotors to a local plating shop and had everything zinc coated to keep them from rusting. They did the brackets in gold and the rotors in clear, well, they called it clear and said they'd look like aluminum. Either way, I like the way everything came out.

A long time ago I used the same tools you used to remove ball joints. That was the last time. For at least 35 years all I use is a large hammer and a little smaller hammer. Hold the large hammer against the one side of the ball joint and hit the other side with the other hammer. I always turn the nut back on a couple threads first to keep it from coming apart. This works well and if you're reusing the ball joint it doesn't hurt the rubber.

It's going to be over a year until I'm driving my car. At least I hope it doesn't take longer than that to finish. Post a review of the difference and if you feel they were worth the cost when you're finished. I'm sure I'm not the only one here that'd like to know.

 

[Frank Odenthal]

This is a case study in why a lot of us prefer to use stock components for the disc conversion. I would be worried about the plate adapter working on the bolts as the holes should be the same size as the bolts to prevent any movement. Keep in mind that there is a tremendous amount of torque on all the brake components on a hard stop, anything that can move will move and in time this could fracture the mounting bolts for the plate. My 2 cents worth.

Dave

Hello Dave,
I totally agree. With my today’s knowledge I would most likely go with stock components as well.
I have know driven the car with this Brake Kit for about 3 month and it works fine so far.
I will make a service and check all bolt tourques very soon in the winter season brake just to be save.
Will give an update on this as well.
Frank

 

[Frank Odenthal]

Update.
That was somewhen in May 2018.
After finishing the preparation of all components, assembly starts.
This is always the funny part of the work, when everything is clean.
I preferred to paint the parts black, instead of the shiny zinc look.

 

[Cazman]

Great write up. Thanks.

 

[stubs300]

I went the SSBC route on all 4 corners and got a good package deal when I did mine. I wanted to keep the 14"ers is the main reason why I went that route. The only thing I found was that I had to use a 1/2" spacer on the fronts for rim clearance, don't know why but did? Looks good!

 

[Frank Odenthal]

My 66‘ 300 stood on 15 x 7“ Magnum 500. I wanted to keep them as well.
Once I did the first trial to put them on the hub, I noticed the magnums touched the calipers.
With the center caps mounted, the wheel stucks on them as well before sitting flat on the hub mounting surface.
Minimum 1/2“ spacers are required to clear the center cap and caliper with the Magnum Wheels.
To be on the save side with some clearance I need to add an additional 3mm spacer.

With this spacer thickness, the lug nuts did not have enough engagement with the studs as well as the universal spacers where not sitting centric.

This was the point for the next unexpected decision. Should or need I go with different wheels ?

The wheel vintigues 15x7 Magnum 500 wheel has an +6mm Offset and the specific inner shape of the wheel does not provide enough clearance, compared to modern Aluminium wheels of the same size.
I always loved the wheel style and the shiny chrome finish, but was unhappy with its heavy weight and poor straightness/runout.
So I added new rims and tires to the final bill.
Will show that in one of the next updates.

 

[Frank Odenthal]

Update May 23rd.
To go ahead with conversion I wanted to make the Magnums fit.
The long caliper bolts had interference with the weld of the rim and the hub cap with the center bore of the rim.
The hub cap had lots of material, so it could be machined to a smaller diameter.
The bolts have been shortened by 5mm.
But there was still a collision with the caliper without spacers.
I had a set of 12mm and 3mm, which used together make the rim fit without scratching any component.

The spacers did not center on the hub and had wide openings for being universal.
That makes them moving in all directions not providing a solid ground for the rims.
Just a provisional solution for a test drive...

 

[Frank Odenthal]

I want to complete the conversion story with some details of the Master and Booster combo and the required brake pedal modification. My 33 300 was originally equipped with a single diaphragm power booster. I did not want to keep it, because it was old, worn and I learned from this forum it will not provide required power support.
I went with a BENDIX style booster and the dual master cylinder wich came with the MP-Brake conversion kit. Both fit together without any problems.
A problem was the new booster's push rod, which was about 22mm shorter then the OEM part.
There was not enough free length between the boot and the attachment to cut the rod and fabricate any enlargement. Therefore I decided to move the pivot point on the Brake Pedal by 22mm.
As there was not enough material in the pedal the pivot point would sit half way outside the material.
To solve this, a machined part was inserted and welded to the pedal. Finally the pivot bore was drilled to the correct size of the fastener connecting it with the push rod eye.

So far this works great and the Pedal rests in the correct position relative to the gas pedal and vehicle floor.

Original OEM setup

New Booster puh rod to short

Brake pedal modification

 

[C-440-300]

I want to complete the conversion story with some details of the Master and Booster combo and the required brake pedal modification. My 33 300 was originally equipped with a single diaphragm power booster. I did not want to keep it, because it was old, worn and I learned from this forum it will not provide required power support.
I went with a BENDIX style booster and the dual master cylinder wich came with the MP-Brake conversion kit. Both fit together without any problems.
A problem was the new booster's push rod, which was about 22mm shorter then the OEM part.
There was not enough free length between the boot and the attachment to cut the rod and fabricate any enlargement. Therefore I decided to move the pivot point on the Brake Pedal by 22mm.
As there was not enough material in the pedal the pivot point would sit half way outside the material.
To solve this, a machined part was inserted and welded to the pedal. Finally the pivot bore was drilled to the correct size of the fastener connecting it with the push rod eye.

So far this works great and the Pedal rests in the correct position relative to the gas pedal and vehicle floor.

I want to complete the conversion story with some details of the Master and Booster combo and the required brake pedal modification. My 33 300 was originally equipped with a single diaphragm power booster. I did not want to keep it, because it was old, worn and I learned from this forum it will not provide required power support.
I went with a BENDIX style booster and the dual master cylinder wich came with the MP-Brake conversion kit. Both fit together without any problems.
A problem was the new booster's push rod, which was about 22mm shorter then the OEM part.
There was not enough free length between the boot and the attachment to cut the rod and fabricate any enlargement. Therefore I decided to move the pivot point on the Brake Pedal by 22mm.
As there was not enough material in the pedal the pivot point would sit half way outside the material.
To solve this, a machined part was inserted and welded to the pedal. Finally the pivot bore was drilled to the correct size of the fastener connecting it with the push rod eye.

So far this works great and the Pedal rests in the correct position relative to the gas pedal and vehicle floor.

Happy New Year (It's still new to me, because I keep writing "2018" on stuff.), Frank! This may sound dumb, but, if not a new push rod, would it have made sense to move the booster further into the engine bay/spacers or something? Brake pedals are some of the strongest steel on the car. At least, if I see correctly, your new hole is on the compression side of the business. Thanks for the work on posting, too. 'Keep her running!

 

[C-440-300]

I went the SSBC route on all 4 corners and got a good package deal when I did mine. I wanted to keep the 14"ers is the main reason why I went that route. The only thing I found was that I had to use a 1/2" spacer on the fronts for rim clearance, don't know why but did? Looks good!

I, also, went SSBC on the '66 300, based on limited review. I noticed that I still had to push a lot harder than I expected to get the beast to stop. The salesman said I would feel night/day difference. More like night and dawn. After reading Frank O's comment about The Forum's opinion on booster choice, can anyone recommend a replacement to my stock unit? (Are half of you saying #@^!&^ That's my issue? ) Dual booster/4-disc on original 4-drum. Thank you, All. [@Stubs300 - My dad flew for The Man in SAC. Was he your boss, also? Thank you for your service.]

 

[stubs300]

No, but I was in SAC and every SAC warrior as well as myself admires the man!