Notices
1961 - 1966 F-100 & Larger F-Series Trucks Discuss the Slick Sixties Ford Truck

1966 Single Pot Drum/Drum Conversion Question

Thread Tools
 
Search this Thread
 
Old Mar 19, 2014 | 09:55 PM
  #1  
K.Ray's Avatar
K.Ray
Thread Starter
|
Freshman User
Joined: Mar 2014
Posts: 37
Likes: 0
1966 Single Pot Drum/Drum Conversion Question

My 66' is currently single pot master cylinder drum/drum setup. I'm in the middle of replacing all of my hardline and figured it was a good time to make the jump to a dual pot master cylinder. I have one from a drum/drum 68' mustang. Will it bolt right up and work or do I need to add things?

Also, what's typical plumbing for this swap? I've found a ton of info on the disc/drum swap but very little for keeping drum/drum in place. Could I just plumb the rear straight from the front pot, and plumb a T fitting into the front from the rear pot?
 
Reply
Old Mar 19, 2014 | 11:37 PM
  #2  
smokenchoken's Avatar
smokenchoken
Fleet Mechanic
10 Year Member
Joined: May 2012
Posts: 1,724
Likes: 1
From: peru kansas
i know it was kind of a no no but i could not get the lines out of my proportioning valve other than the one that leads to the back brakes so i plugged off the rear brake line hole in proportioning valve and replaced hard line leading to the back brakes and never had a problem.... i used the dual pot M/C off of my 67 aka smokenchoke it was a direct swap into my 66 don't forget to rig up a new form of brake light since the old brake light used to be hooked up to a pressure sensor on the single pot..... i used the switch from a 72 and some scrap iron to mount it but you might want something a little better looking
 
Reply
Old Mar 20, 2014 | 05:30 AM
  #3  
jowilker's Avatar
jowilker
Fleet Owner
25 Year Member
Joined: Jun 1999
Posts: 24,552
Likes: 74
From: Creedmoor, North Carolina
Club FTE Silver Member

Ray, Why don't you do the real upgrade and instead of a half A project go with a power disc brake upgrade using a 73-79 donor?



John
 
Reply
Old Mar 20, 2014 | 06:24 AM
  #4  
K.Ray's Avatar
K.Ray
Thread Starter
|
Freshman User
Joined: Mar 2014
Posts: 37
Likes: 0
Originally Posted by jowilker
Ray, Why don't you do the real upgrade and instead of a half A project go with a power disc brake upgrade using a 73-79 donor?



John
Would love to, but right now just want the truck on the road so I can use it. I'll do a disc swap after other priorities are taken care of. Still need to rebuild the fuel system, rebuild the electrical system, rebuild the cab floor, rebuild the bed floor, sort the lights out, source new wheels and tires.
 
Reply
Old Mar 20, 2014 | 06:27 AM
  #5  
K.Ray's Avatar
K.Ray
Thread Starter
|
Freshman User
Joined: Mar 2014
Posts: 37
Likes: 0
Originally Posted by smokenchoken
i know it was kind of a no no but i could not get the lines out of my proportioning valve other than the one that leads to the back brakes so i plugged off the rear brake line hole in proportioning valve and replaced hard line leading to the back brakes and never had a problem.... i used the dual pot M/C off of my 67 aka smokenchoke it was a direct swap into my 66 don't forget to rig up a new form of brake light since the old brake light used to be hooked up to a pressure sensor on the single pot..... i used the switch from a 72 and some scrap iron to mount it but you might want something a little better looking
I don't see why that wouldn't work. I'm terrible with this "custom" stuff. I typically strive to keep things as they were intended, but the brakes seem like a safety issue.
 
Reply
Old Mar 20, 2014 | 06:48 AM
  #6  
Shadowrider123's Avatar
Shadowrider123
Fleet Mechanic
15 Year Member
Photogenic
Joined: Oct 2007
Posts: 1,992
Likes: 120
I don't think the Mustang MC will work for you.

I seem to remember that 67 was a unique year, so I think a 68-72 MC will work fine.

A MC only runs about $20 + core deposit, so less than $30 total Im guessing.
 
Reply
Old Mar 20, 2014 | 07:31 AM
  #7  
K.Ray's Avatar
K.Ray
Thread Starter
|
Freshman User
Joined: Mar 2014
Posts: 37
Likes: 0
Originally Posted by Shadowrider123
I don't think the Mustang MC will work for you.

I seem to remember that 67 was a unique year, so I think a 68-72 MC will work fine.

A MC only runs about $20 + core deposit, so less than $30 total Im guessing.
My MC is from a 68 with drum/drum setup. I guess I could just use it as a core, worst case.
 
Reply
Old Mar 20, 2014 | 09:13 AM
  #8  
NumberDummy's Avatar
NumberDummy
Ford Parts Specialist
Joined: Nov 2006
Posts: 88,826
Likes: 787
From: Simi Valley, CA
Club FTE Gold Member
Originally Posted by Shadowrider123
I don't think the Mustang MC will work for you.

I seem to remember that 67 was a unique year related to F100/350 only.
1967/70 Mustang/Cougar with power DRUM brakes use the same master cylinder (C7ZZ-2140-G).

1967/72 Mustang/Cougar with power DISC brakes use a different master cylinder (C8ZZ-2140-A) than with power DRUM brakes.

1967/70 Mustang/Cougar with MANUAL drum brakes use a different master cylinder (C9AZ-2140-D) than with power drum or disc brakes.
-----------------------------------------------------------------------------------------------------------------------------------------------------------------
1967 F100/350 use one year only master cylinders, power brake boosters and brake pressure differential valves, 2WD different from 4WD.

The brake and clutch pedals, brake lamp switch, bracket under the dash the pedals suspend from, is also 1967 only.
------------------------------------------------------------------------------------------------------------------------------------------
All 1940/66 trucks use the same brake lamp switch (C1AZ-13480-A [replaced 0A-13480] Motorcraft SW-24), located at the front of the master cylinder.

It's pressure activated by stepping on the pedal. It's also notorious for getting gummed up with dirty brake fluid.

Beginning 1967, the brake lamp switch attaches to a bracket on the brake pedal, but 1967's use a one year only switch and pedal.
 
Reply
FTE Stories

Ford Trucks for Ford Truck Enthusiasts

story-0

10 Ways Ford is LOSING to the Competition

 Joe Kucinski
story-1

Top 6 Best Deals Available on New Fords & Lincolns Right Now

 Brett Foote
story-2

This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level

 Verdad Gallardo
story-3

Top 10 Fords at 2026 Carlisle Ford Nationals

 Joe Kucinski
story-4

3 Best / 3 Worst Parts of Modern Ford Ownership

 Brett Foote
story-5

10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches

 Pouria Savadkouei
story-6

Every 2026 Ford Engine Explained

 Brett Foote
story-7

10 Ugly Ford Trucks That We Still Kinda Love

 Joe Kucinski
story-8

10 Things Every Truck Owner NEEDS (2026 Edition)

 Michael S. Palmer
story-9

Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath

 Verdad Gallardo
Old Mar 20, 2014 | 09:28 AM
  #9  
K.Ray's Avatar
K.Ray
Thread Starter
|
Freshman User
Joined: Mar 2014
Posts: 37
Likes: 0
Originally Posted by NumberDummy
1967/70 Mustang/Cougar with power DRUM brakes use the same master cylinder (C7ZZ-2140-G).

1967/72 Mustang/Cougar with power DISC brakes use a different master cylinder (C8ZZ-2140-A) than with power DRUM brakes.

1967/70 Mustang/Cougar with MANUAL drum brakes use a different master cylinder (C9AZ-2140-D) than with power drum or disc brakes.

1967 F100/350 use one year only master cylinders, power brake boosters and brake pressure differential valves. 2WD different from 4WD.

The brake and clutch pedals, bracket under the dash they suspend from, also 1967 only.

So, according to paperwork, my 66 F100 should be fine to utilize the 68 mustang non-power non-booster drum/drum mustang MC - correct?

And it has built-in resisters for drum brakes front/rear, so all I have to do is hook like up and I'm good to go. Easy-peasy.
 
Reply
Old Mar 20, 2014 | 09:46 AM
  #10  
NumberDummy's Avatar
NumberDummy
Ford Parts Specialist
Joined: Nov 2006
Posts: 88,826
Likes: 787
From: Simi Valley, CA
Club FTE Gold Member
Originally Posted by K.Ray
So, according to paperwork, my 66 F100 should be fine to utilize the 68 mustang non-power non-booster drum/drum mustang MC - correct?

And it has built-in resisters for drum brakes front/rear, so all I have to do is hook like up and I'm good to go. Easy-peasy.
Dual master cylinders require a brake pressure differential valve aka proportioning valve.

You will also need to adapt a brake lamp switch that attaches to the pedal. See edited post #8.
 
Reply
Old Mar 20, 2014 | 09:49 AM
  #11  
K.Ray's Avatar
K.Ray
Thread Starter
|
Freshman User
Joined: Mar 2014
Posts: 37
Likes: 0
Originally Posted by NumberDummy
Dual master cylinders require a brake pressure differential valve aka proportioning valve.

You will also need to adapt a brake lamp switch that attaches to the pedal. See edited post #8.
Okay, thank you for the clarification. So something like this should solve all my issues?
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
NEA72
1967 - 1972 F-100 & Larger F-Series Trucks
15
Apr 24, 2014 07:40 PM
flipklos
1961 - 1966 F-100 & Larger F-Series Trucks
5
Jun 7, 2011 07:02 PM
fun98
1948 - 1956 F1, F100 & Larger F-Series Trucks
4
May 20, 2008 09:42 PM
clancassidy
1961 - 1966 F-100 & Larger F-Series Trucks
5
Jan 13, 2007 05:29 PM
Hayesn
1961 - 1966 F-100 & Larger F-Series Trucks
7
Jul 4, 2006 03:55 PM




All times are GMT -5. The time now is 07:34 PM.

story-0
10 Ways Ford is LOSING to the Competition

Slideshow: 10 ways Ford is losing to the competition

By Joe Kucinski | 2026-06-15 09:52:01


VIEW MORE
story-1
Top 6 Best Deals Available on New Fords & Lincolns Right Now

Some great targets in today's expensive world.

By Brett Foote | 2026-06-15 09:35:19


VIEW MORE
story-2
This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level

Slideshow: The VelociRaptor Expedition gains a lift, upgraded suspension, Brembo brakes, and trail-ready equipment while retaining the stock 440-horsepower EcoBoost V6.

By Verdad Gallardo | 2026-06-12 11:01:55


VIEW MORE
story-3
Top 10 Fords at 2026 Carlisle Ford Nationals

Slideshow: Top 10 Fords at 2026 Ford Nationals

By Joe Kucinski | 2026-06-09 11:10:08


VIEW MORE
story-4
3 Best / 3 Worst Parts of Modern Ford Ownership

Based on years of owning multiple modern Ford products.

By Brett Foote | 2026-06-09 10:53:36


VIEW MORE
story-5
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches

SPONSORED: From muddy boots to rain-soaked cargo, these upgrades address some of the most common frustrations Ford truck owners face every day.

By Pouria Savadkouei | 2026-06-08 18:50:34


VIEW MORE
story-6
Every 2026 Ford Engine Explained

Here's everything you need to know about every Ford engine available for the 2026 model year.

By Brett Foote | 2026-06-05 12:58:01


VIEW MORE
story-7
10 Ugly Ford Trucks That We Still Kinda Love

Slideshow: 10 ugly Ford trucks that we still kinda love.

By Joe Kucinski | 2026-06-03 09:51:16


VIEW MORE
story-8
10 Things Every Truck Owner NEEDS (2026 Edition)

Slideshow: the best gifts for dads & grads

By Michael S. Palmer | 2026-06-03 15:43:58


VIEW MORE
story-9
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath

Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.

By Verdad Gallardo | 2026-06-03 11:38:36


VIEW MORE