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 1967 - 1972 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 08-10-2022, 05:18 PM   #1
don t. - 72gmc
Registered User
 
Join Date: Dec 2001
Location: harvard, il. USA
Posts: 389
Brake booster install

70 GMC C20

Never played w/a booster before.

Bought a new one...



Old booster rod length is 8 3/4" from housing to end of rod.
New rod was to long....


Removed old rod, installed on new booster.
Slid rod in hole. Bolted booster to firewall.
Bolted rod end to brake pedal, installed cotter pin.

Anything I should be worried about?

Thanks much...Don.
don t. - 72gmc is offline   Reply With Quote
Old 08-10-2022, 06:07 PM   #2
leftybass209
Registered User
 
leftybass209's Avatar
 
Join Date: Feb 2011
Location: Modesto, CA
Posts: 2,184
Re: Brake booster install

make sure that the linkage doesn't contact the firewall when you have the pedal height where you want it. I just did a conversion with an 8" booster and that's one of the things the instructions pointed out. I had to cut the booster rod about 1".

Might be different for the brackets on the 11" booster.

Best of luck!
leftybass209 is offline   Reply With Quote
Old 08-11-2022, 12:12 AM   #3
ProjectHarold72
Registered User
 
Join Date: May 2022
Location: Goshen, OH
Posts: 12
Re: Brake booster install

Getting ready to do the exact same thing in my 72. Never done it before but have researched the heck out of it online and hoping that will be enough to make it all come together. I'm sure you have seen this already but be sure you bench bleed the master before hooking up your lines. Good luck on your install!
ProjectHarold72 is offline   Reply With Quote
Old 08-11-2022, 08:08 AM   #4
don t. - 72gmc
Registered User
 
Join Date: Dec 2001
Location: harvard, il. USA
Posts: 389
Re: Brake booster install

Initially, I was a bit worried about the size difference between old and new, but it bolted on w/no issue. I was thinking of cutting it but it was a ton easier to swap em.

Yep bleeding everything is a week or so out.

Thanks much...Don
don t. - 72gmc is offline   Reply With Quote
Old 08-11-2022, 09:32 AM   #5
72SB
Registered User
 
Join Date: Apr 2022
Location: Moorpark, CA
Posts: 696
Re: Brake booster install

While the rods may be different lengths....make sure the booster brackets are also (read are new ones longer?) as you may need the one that came with the new booster

I just replaced my non power MC with a power MC/Booster (CPP) and it was plug & play relative to using the rod that came with new booster.

You do want to remove MC from new booster and bench bleed it before installing on truck
72SB is offline   Reply With Quote
Old 08-11-2022, 04:01 PM   #6
Sheepdip
Senior Member
 
Sheepdip's Avatar
 
Join Date: Nov 2018
Location: Waterford California
Posts: 2,360
Re: Brake booster install

Someone chime in if I'm 180 out, but I was under the impression the dual diaphragm like the old one shown here was for added stopping power for loaded 3/4- and 1-ton trucks

I'm sure the single will work but not as engineered by GM
Sheepdip is offline   Reply With Quote
Old 08-11-2022, 09:25 PM   #7
Accelo
Registered User
 
Accelo's Avatar
 
Join Date: Mar 2015
Location: washington
Posts: 2,151
Re: Brake booster install

I surely am interested in the difference between the firewall to the master cylinder overall length differences.
Accelo is offline   Reply With Quote
Old 08-14-2022, 08:43 AM   #8
don t. - 72gmc
Registered User
 
Join Date: Dec 2001
Location: harvard, il. USA
Posts: 389
Re: Brake booster install

Quote:
Originally Posted by Sheepdip View Post
Someone chime in if I'm 180 out, but I was under the impression the dual diaphragm like the old one shown here was for added stopping power for loaded 3/4- and 1-ton trucks

I'm sure the single will work but not as engineered by GM
I was a bit concerned when I received the part, the overall difference between the 2. I checked the site I purchased, overall did a google. From what I could tell, the new part is all that is available. As you stated, my C20 will not do the work it once did, and should be fine.


Quote:
Originally Posted by Accelo View Post
I surely am interested in the difference between the firewall to the master cylinder overall length differences.
I'll get you the measurements tomorrow.
don t. - 72gmc is offline   Reply With Quote
Old 08-15-2022, 02:52 PM   #9
don t. - 72gmc
Registered User
 
Join Date: Dec 2001
Location: harvard, il. USA
Posts: 389
Re: Brake booster install

Quote:
Originally Posted by Accelo View Post
I surely am interested in the difference between the firewall to the master cylinder overall length differences.
From the firewall to where the master mounts to the new booster = 9 3/16"

Same measurement of the old booster is a bit short of 10", maybe 9 7/8"

HTH...Don.
don t. - 72gmc is offline   Reply With Quote
Old 08-15-2022, 06:02 PM   #10
Accelo
Registered User
 
Accelo's Avatar
 
Join Date: Mar 2015
Location: washington
Posts: 2,151
Re: Brake booster install

Thanks Don.
Not enough to account for my lines being so far off.
Has to be in the lines not the master/booster set up.
Cheers
Accelo is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

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 08:56 AM.


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