The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1960 - 1966 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 10-15-2020, 09:14 PM   #1
Asshat
Registered User
 
Asshat's Avatar
 
Join Date: Jul 2015
Location: South Orange County CA
Posts: 1,265
Upgrade from single master to vacuum boost dual master - 63 C20

On the advice of many here, I would like to upgrade the master cylinder. It still has drum brakes- hope that is not an issue.

Can I just buy a dual master and booster from Rock Auto or is the Truck Shop better? Isn’t there a special bracket I need from Captain Fab?
__________________
1963 C20, small window, long bed
292, 4-speed
Asshat is offline   Reply With Quote
Old 10-15-2020, 09:42 PM   #2
Captainfab
60-66 Nut

 
Join Date: Mar 2007
Location: Coeur d'Alene, Idaho
Posts: 23,252
Re: Upgrade from single master to vacuum boost dual master - 63 C20

For what you are doing I would recommend a booster and master assembly for a '67-'70 C20. Yes it will bolt up to my '63-'66 standard booster bracket.
__________________
Power Steering Box Adapter Plates For Sale HERE
Power Brake Booster Adapter Brackets For Sale '63-'66 HERE and '67-'72 HERE and '60-'62 HERE and "60-'62 with clutch HERE
Rear Disc Brake Brackets For Sale. Impala SS calipers HERE Camaro Calipers HERE D52 Calipers HERE 6 Lug HERE
Hydroboost Mounting Plates HERE
Captainfab is offline   Reply With Quote
Old 10-15-2020, 11:02 PM   #3
Asshat
Registered User
 
Asshat's Avatar
 
Join Date: Jul 2015
Location: South Orange County CA
Posts: 1,265
Re: Upgrade from single master to vacuum boost dual master - 63 C20

Quote:
Originally Posted by Captainfab View Post
For what you are doing I would recommend a booster and master assembly for a '67-'70 C20. Yes it will bolt up to my '63-'66 standard booster bracket.
Cool. How much for that bracket?
__________________
1963 C20, small window, long bed
292, 4-speed
Asshat is offline   Reply With Quote
Old 10-15-2020, 11:08 PM   #4
Steeveedee
Who Changed This?
 
Steeveedee's Avatar
 
Join Date: Jan 2013
Location: Simi Valley, CA
Posts: 10,693
Re: Upgrade from single master to vacuum boost dual master - 63 C20

Captain, do you sell the rest of the hydraulic stuff that he will need? Or can you point him to a source?
__________________
~Steven

'70 Chevy 3/4T Longhorn CST 402/400/3.56 Custom Camper

Simi Valley, CA
Steeveedee is offline   Reply With Quote
Old 10-16-2020, 04:07 PM   #5
LostMy65
But Found Her 25yrs Later!
 
LostMy65's Avatar
 
Join Date: Oct 2010
Location: Oregon City, Oregon
Posts: 10,530
Re: Upgrade from single master to vacuum boost dual master - 63 C20

With a C20, you'll be happy with power drum brakes. And the dual master cylinder adds even more safety.

Here's a good thread from the FAQs:
http://67-72chevytrucks.com/vboard/s...d.php?t=332148

I also added one of these to the rear line so I could adjust for a loaded or unloaded bed. It's not necessary though.
https://www.summitracing.com/parts/s...BoCH9kQAvD_BwE
__________________
I lost my 65 - Found it 25 years later:
http://67-72chevytrucks.com/vboard/s...d.php?t=426650

66 C20 Service Truck:
http://67-72chevytrucks.com/vboard/s...d.php?t=428035
LostMy65 is offline   Reply With Quote
Old 10-16-2020, 09:35 PM   #6
Captainfab
60-66 Nut

 
Join Date: Mar 2007
Location: Coeur d'Alene, Idaho
Posts: 23,252
Re: Upgrade from single master to vacuum boost dual master - 63 C20

Quote:
Originally Posted by Asshat View Post
Cool. How much for that bracket?
The '63-'66 standard booster bracket is the same price as in post #1 of the for sale thread.

http://www.67-72chevytrucks.com/vboa...d.php?t=339081

Quote:
Originally Posted by Steeveedee View Post
Captain, do you sell the rest of the hydraulic stuff that he will need? Or can you point him to a source?
I don't see where the OP said anything about converting to a hydraulic clutch.
__________________
Power Steering Box Adapter Plates For Sale HERE
Power Brake Booster Adapter Brackets For Sale '63-'66 HERE and '67-'72 HERE and '60-'62 HERE and "60-'62 with clutch HERE
Rear Disc Brake Brackets For Sale. Impala SS calipers HERE Camaro Calipers HERE D52 Calipers HERE 6 Lug HERE
Hydroboost Mounting Plates HERE
Captainfab is offline   Reply With Quote
Old 10-17-2020, 07:28 AM   #7
Asshat
Registered User
 
Asshat's Avatar
 
Join Date: Jul 2015
Location: South Orange County CA
Posts: 1,265
Re: Upgrade from single master to vacuum boost dual master - 63 C20

Quote:
Originally Posted by LostMy65 View Post
With a C20, you'll be happy with power drum brakes. And the dual master cylinder adds even more safety.

Here's a good thread from the FAQs:
http://67-72chevytrucks.com/vboard/s...d.php?t=332148

I also added one of these to the rear line so I could adjust for a loaded or unloaded bed. It's not necessary though.
https://www.summitracing.com/parts/s...BoCH9kQAvD_BwE
Hey - thanks for the link.
However, there are no pics showing up, probably since the thread is so old.

Bottom line, do just need to split the lines, so the front of the master goes to the front brakes, and the rear of the master goes to the back brakes?
__________________
1963 C20, small window, long bed
292, 4-speed
Asshat is offline   Reply With Quote
Old 10-17-2020, 03:16 PM   #8
LostMy65
But Found Her 25yrs Later!
 
LostMy65's Avatar
 
Join Date: Oct 2010
Location: Oregon City, Oregon
Posts: 10,530
Re: Upgrade from single master to vacuum boost dual master - 63 C20

Quote:
Originally Posted by Asshat View Post
Hey - thanks for the link.
However, there are no pics showing up, probably since the thread is so old.

Bottom line, do just need to split the lines, so the front of the master goes to the front brakes, and the rear of the master goes to the back brakes?
For some reason I thought the rear port went to the front brakes, but with drums it may not matter.
.
Also, I just went to the thread on my phone - the pics are there.
Here is part of the pics as screenshots starting from top to bottom.
Attached Images
     
__________________
I lost my 65 - Found it 25 years later:
http://67-72chevytrucks.com/vboard/s...d.php?t=426650

66 C20 Service Truck:
http://67-72chevytrucks.com/vboard/s...d.php?t=428035
LostMy65 is offline   Reply With Quote
Old 10-17-2020, 03:22 PM   #9
LostMy65
But Found Her 25yrs Later!
 
LostMy65's Avatar
 
Join Date: Oct 2010
Location: Oregon City, Oregon
Posts: 10,530
Re: Upgrade from single master to vacuum boost dual master - 63 C20

I'm trying to post the rest, but I keep getting a security token issue message.
Give me a few.
Attached Images
  
__________________
I lost my 65 - Found it 25 years later:
http://67-72chevytrucks.com/vboard/s...d.php?t=426650

66 C20 Service Truck:
http://67-72chevytrucks.com/vboard/s...d.php?t=428035
LostMy65 is offline   Reply With Quote
Old 10-17-2020, 03:23 PM   #10
LostMy65
But Found Her 25yrs Later!
 
LostMy65's Avatar
 
Join Date: Oct 2010
Location: Oregon City, Oregon
Posts: 10,530
Re: Upgrade from single master to vacuum boost dual master - 63 C20

Here's the rest.
Attached Images
   
__________________
I lost my 65 - Found it 25 years later:
http://67-72chevytrucks.com/vboard/s...d.php?t=426650

66 C20 Service Truck:
http://67-72chevytrucks.com/vboard/s...d.php?t=428035
LostMy65 is offline   Reply With Quote
Old 10-17-2020, 04:03 PM   #11
LostMy65
But Found Her 25yrs Later!
 
LostMy65's Avatar
 
Join Date: Oct 2010
Location: Oregon City, Oregon
Posts: 10,530
Re: Upgrade from single master to vacuum boost dual master - 63 C20

Does that help?
__________________
I lost my 65 - Found it 25 years later:
http://67-72chevytrucks.com/vboard/s...d.php?t=426650

66 C20 Service Truck:
http://67-72chevytrucks.com/vboard/s...d.php?t=428035
LostMy65 is offline   Reply With Quote
Old 10-17-2020, 04:40 PM   #12
LostMy65
But Found Her 25yrs Later!
 
LostMy65's Avatar
 
Join Date: Oct 2010
Location: Oregon City, Oregon
Posts: 10,530
Re: Upgrade from single master to vacuum boost dual master - 63 C20

Just found another thread:
http://67-72chevytrucks.com/vboard/s...d.php?t=487384
And this one was in the FAQs:
http://67-72chevytrucks.com/vboard/s...d.php?t=599582
__________________
I lost my 65 - Found it 25 years later:
http://67-72chevytrucks.com/vboard/s...d.php?t=426650

66 C20 Service Truck:
http://67-72chevytrucks.com/vboard/s...d.php?t=428035

Last edited by LostMy65; 10-17-2020 at 04:49 PM.
LostMy65 is offline   Reply With Quote
Old 10-17-2020, 05:12 PM   #13
Asshat
Registered User
 
Asshat's Avatar
 
Join Date: Jul 2015
Location: South Orange County CA
Posts: 1,265
Re: Upgrade from single master to vacuum boost dual master - 63 C20

Quote:
Originally Posted by LostMy65 View Post
Does that help?
Yes, I will read through it.
Thank you.

It doesn’t show the booster, doesn’t make a difference, does it?
__________________
1963 C20, small window, long bed
292, 4-speed
Asshat is offline   Reply With Quote
Old 10-29-2020, 12:01 AM   #14
Asshat
Registered User
 
Asshat's Avatar
 
Join Date: Jul 2015
Location: South Orange County CA
Posts: 1,265
Re: Upgrade from single master to vacuum boost dual master - 63 C20

Am I missing something? These write-ups just mention the splitting of lines and which master cyl to buy.

Should I just upgrade to the dual master and not worry about the Vacuum booster?

Will the dual master alone improve the braking?
__________________
1963 C20, small window, long bed
292, 4-speed
Asshat is offline   Reply With Quote
Old 10-29-2020, 02:40 AM   #15
LostMy65
But Found Her 25yrs Later!
 
LostMy65's Avatar
 
Join Date: Oct 2010
Location: Oregon City, Oregon
Posts: 10,530
Re: Upgrade from single master to vacuum boost dual master - 63 C20

I would do the booster while you are at it. I feel safer with the dual master cylinder, but I'm 55 and if I have to do a lot of braking on my 65, I definitely feel it in my right leg.
__________________
I lost my 65 - Found it 25 years later:
http://67-72chevytrucks.com/vboard/s...d.php?t=426650

66 C20 Service Truck:
http://67-72chevytrucks.com/vboard/s...d.php?t=428035
LostMy65 is offline   Reply With Quote
Old 10-29-2020, 11:45 AM   #16
Steeveedee
Who Changed This?
 
Steeveedee's Avatar
 
Join Date: Jan 2013
Location: Simi Valley, CA
Posts: 10,693
Re: Upgrade from single master to vacuum boost dual master - 63 C20

Quote:
Originally Posted by Asshat View Post
Am I missing something? These write-ups just mention the splitting of lines and which master cyl to buy.

Should I just upgrade to the dual master and not worry about the Vacuum booster?

Will the dual master alone improve the braking?
The dual master gets you out of serious harm if front or rear brake fail, as you still have "half" the system to brake with. But it doesn't improve the braking itself. You'd need to go to disc brakes for that, and then I'd recommend power brakes.
__________________
~Steven

'70 Chevy 3/4T Longhorn CST 402/400/3.56 Custom Camper

Simi Valley, CA
Steeveedee is offline   Reply With Quote
Old 10-29-2020, 06:34 PM   #17
AcampoDave
Registered User
 
AcampoDave's Avatar
 
Join Date: Feb 2013
Location: central California
Posts: 2,776
Re: Upgrade from single master to vacuum boost dual master - 63 C20

I run manual split system drums on one of my trucks and maual disc/drum on the other. Both stop great and take no more pedal pressure than a well maintained single pot system. I've never liked the look of the booster under the hood so I figured I'd go manual and if I felt like I ever needed to put in a booster I could always do it later. (That was at least 10 years ago and I still don't see a reason to add one). Either truck will lay a skid when I slam the pedal down and they don't stop much quicker than that. The truck with drums in front however, will start to fade under repeated use do to heat.
As far as tired knees go, I've had surgery in both of them and it's only the clutch that feels like a workout in heavy traffic. (More the muscles of the leg than the knee joint itself) Braking is no sweat. Remember though, I have half tons and have no experience with the heavier trucks.
AcampoDave is offline   Reply With Quote
Old 11-01-2020, 03:11 PM   #18
Asshat
Registered User
 
Asshat's Avatar
 
Join Date: Jul 2015
Location: South Orange County CA
Posts: 1,265
Re: Upgrade from single master to vacuum boost dual master - 63 C20

Those Impala master cylinders are not $20 anymore, more like $45 at O’Reilly.
__________________
1963 C20, small window, long bed
292, 4-speed
Asshat is offline   Reply With Quote
Old 11-01-2020, 03:21 PM   #19
studeclunker
Registered User
 
studeclunker's Avatar
 
Join Date: Mar 2007
Location: Fawn Lodge, Ca.
Posts: 305
Re: Upgrade from single master to vacuum boost dual master - 63 C20

Interesting thread and love the pics explaining the process. Wish I was so good at bending pipe!

Question:
Will the dual master bolt right up to my current booster that has a single master cylinder?
Do I have to completely replace the plumbing on my brakes, or can I just replace the lines to the distribution hub?
studeclunker is offline   Reply With Quote
Old 11-02-2020, 10:10 PM   #20
Lugnutz65
Registered User
 
Lugnutz65's Avatar
 
Join Date: Jan 2013
Location: Columbia, SC
Posts: 1,927
Re: Upgrade from single master to vacuum boost dual master - 63 C20

Here’s my contribution in 2 parts.

Part 1 is from my website and shows how I added the CaptainFab bracket and booster with dual MC for front disc brakes. LINK HERE.

Part 2 is a video I made when I still had drum/drum and converted to a dual MC.
VIDEO LINK HERE
Attached Images
 
__________________
My 65 C10 build: www.lugnutz65chevystepside.weebly.com

Want to know more about T5 transmissions? My website has a T5 Info Page and a Step by Step T5 rebuild.
Lugnutz65 is offline   Reply With Quote
Old 11-03-2020, 09:02 PM   #21
jayoldschool
Moderator
 
Join Date: Dec 2012
Location: ON, Canada
Posts: 2,176
Re: Upgrade from single master to vacuum boost dual master - 63 C20

Quote:
Originally Posted by Asshat View Post
Those Impala master cylinders are not $20 anymore, more like $45 at O’Reilly.
Use an Impala master in a car. Put a 67 truck master in your truck ;-)
jayoldschool is offline   Reply With Quote
Old 11-03-2020, 09:28 PM   #22
Asshat
Registered User
 
Asshat's Avatar
 
Join Date: Jul 2015
Location: South Orange County CA
Posts: 1,265
Re: Upgrade from single master to vacuum boost dual master - 63 C20

Quote:
Originally Posted by jayoldschool View Post
Use an Impala master in a car. Put a 67 truck master in your truck ;-)
What do you do if the mounting holes are not inline horizontally? Mine are offset, one side is higher than the other.
__________________
1963 C20, small window, long bed
292, 4-speed
Asshat is offline   Reply With Quote
Old 11-03-2020, 09:33 PM   #23
The Rocknrod
Moderator

 
The Rocknrod's Avatar
 
Join Date: Aug 2011
Location: China Spring, TX
Posts: 7,280
Re: Upgrade from single master to vacuum boost dual master - 63 C20

Quote:
Originally Posted by Asshat View Post
What do you do if the mounting holes are not inline horizontally? Mine are offset, one side is higher than the other.
http://www.67-72chevytrucks.com/vboa...=1#post3257836
The Rocknrod is offline   Reply With Quote
Old 11-06-2020, 08:47 PM   #24
theastronaut
Registered User
 
theastronaut's Avatar
 
Join Date: May 2011
Location: Anderson SC
Posts: 3,901
Re: Upgrade from single master to vacuum boost dual master - 63 C20

A booster is not neccessary if you do disc with pads that have a good compound and bite hard on their own. If you use ceramic pads that have a low coefficient of friction then it'll take excessive pedal pressure to make the truck stop with manual brakes. If you use a semi-metallic pad that has a more aggressive coefficient of friction it'll bite harder and stop easier with reasonable pedal pressure and not need a booster.

My problem with discs and a booster is that it can very easily have the problem of having too soft of a pedal, and modulating braking under emergency stop conditions becomes impossible.

These are just made up numbers and are extreme examples to prove a point, but lets say it takes ten pounds of pedal force to lock up the brakes, and nine pounds to stop as hard as possible without lockup. Can you vary the pedal pressure by only one pound to keep from skidding in an emergency stop situation? Or vary only one pound between 80% and 90% stopping ability? Thats really hard to do.

Then lets say a manual system locks up at 100 pounds, and max braking without lock up is 90 pounds of effort- you can more easily vary how much pressure you're applying to the pedal and stop as hard as possible without lock up because there's a wider range of pedal force needed between controllable braking and lock up.

The other issue I have with boosters is that some are overboosted so the pedal is very touchy and there's no feedback through the pedal. That makes braking accurately very hard.


My favorite setup was my old '66 with a CPP front disc kit with semi-metalic pads, rebuilt stock rear drums, and a non-power dual circuit master cylinder that was the same internal diameter as the original single circuit manual master cylinder. The smaller internal bore increases line pressure, which along with the disc made plenty of stopping power with reasonable pedal pressure and easy modulation of braking force needed to stop hard without locking up.


Issue number two... using tires that have a good compound and can actually stop harder without locking up as easily. More powerful brakes are pointless if you have a tire that is just going to skid.
theastronaut is offline   Reply With Quote
Old 11-06-2020, 09:08 PM   #25
Lugnutz65
Registered User
 
Lugnutz65's Avatar
 
Join Date: Jan 2013
Location: Columbia, SC
Posts: 1,927
Re: Upgrade from single master to vacuum boost dual master - 63 C20

The Astronaut,
Let’s see if you agree.
A smaller bore MC is less touchy because it pushes less fluid during the stroke compared to a larger bore making the same length stroke. Therefore a smaller bore MC is less sensitive or “touchy” than a larger bore MC.

Another method that can reduce the “touchy” feeling of boosted disc brakes is to drill a new hole where the pushrod connects to brake pedal arm. Most articles suggest moving the connection hole down 1”. Moving the pushrod down reduces the mechanical leverage from 9:1 to maybe 7.5 to 1.
__________________
My 65 C10 build: www.lugnutz65chevystepside.weebly.com

Want to know more about T5 transmissions? My website has a T5 Info Page and a Step by Step T5 rebuild.
Lugnutz65 is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 01:30 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com