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 04-18-2018, 09:43 AM   #1
jfnar
Registered User
 
Join Date: Jul 2009
Location: Jonesboro, AR
Posts: 410
Sagging master cylinder

I'm trying to finish up my disc brake upgrade on my 68 gmc but keep running into challenges. I found yesterday that the booster is very close to the holly 4 bbl carb on the 292. My brand new 10" air cleaner will interfere and I'll have to modify the throttle linkage. I have a plan for those issues. Next I noticed that the booster/master cylinder assembly is sloping down toward the front. I don't know if that causes any problems with the functionality but I would prefer for it to be level. Should I shim the mounting bolts at the firewall to level it up? Any other suggestions? Thanks.
Attached Images
  
jfnar is offline   Reply With Quote
Old 04-18-2018, 11:08 AM   #2
B. W.
Registered User
 
B. W.'s Avatar
 
Join Date: Nov 2014
Location: Bigfork, Montana
Posts: 1,137
Re: Sagging master cylinder

It's mounted correctly. They all run down hill for some reason.
B. W. is offline   Reply With Quote
Old 04-18-2018, 11:35 AM   #3
jjzepplin
Registered User
 
jjzepplin's Avatar
 
Join Date: Feb 2012
Location: Ruskin Florida
Posts: 4,535
Re: Sagging master cylinder

Mine is 3/4 ton and is very similar in angle.
__________________
70 swb 4x4 406sbc 700r4 203/205 d60/14blt locker yadda yadda http://67-72chevytrucks.com/vboard/s...88#post6935688 Yeller
72 Blazer 2wd conversion project "No Daggum Money" http://67-72chevytrucks.com/vboard/s...d.php?t=550804 LS1-T56 3.73 LSD super budget build
Blanco-2014 Sierra SWB https://67-72chevytrucks.com/vboard/...d.php?t=810350
jjzepplin is offline   Reply With Quote
Old 04-18-2018, 11:48 AM   #4
jfnar
Registered User
 
Join Date: Jul 2009
Location: Jonesboro, AR
Posts: 410
Re: Sagging master cylinder

Thanks for the input. It looks a little sad but as long as it works I'll leave it alone.
jfnar is offline   Reply With Quote
Old 04-18-2018, 01:36 PM   #5
HIGHWAY BY THE SEA
Registered User
 
HIGHWAY BY THE SEA's Avatar
 
Join Date: Nov 2012
Location: BY THE CAROLINA SEA
Posts: 916
Re: Sagging master cylinder

I just had a disc conversion done on my 68, and my new master cylinder is a mile from the firewall now! No clearance issues with the breather because I put a smaller one on there.
__________________
FRANKENTRUCK 1981 Chevrolet C10 Shortbed Stepside
GRANDTRUCK 1968 Chevrolet C10 Stepside Longbed
http://67-72chevytrucks.com/vboard/s...d.php?t=584617
PROJECT JIGSAW 1967 GMC C3500
GREAT WHITE 1986 Blazer M1009
HIGHWAY BY THE SEA is offline   Reply With Quote
Old 04-19-2018, 05:52 AM   #6
panhead59
Registered User
 
Join Date: Feb 2012
Location: Vinton, Va.
Posts: 473
Re: Sagging master cylinder

By the way- Those stock brake lines will bend and fit nice if you're REAL careful. I just did mine. Just bend and don't twist. Good luck. Go slow and it'll work!!!!
panhead59 is offline   Reply With Quote
Old 04-19-2018, 11:05 AM   #7
demian5
Registered User
 
demian5's Avatar
 
Join Date: Aug 2016
Location: Lake Forest, CA
Posts: 2,177
Re: Sagging master cylinder

Only thing I don't like is that if you have any slight issue with the gasket for the cap, your frame rail is swimming in brake fluid.
__________________
"Work hard, use your vacation days."
1970 C15 GMC Long Bed
1986 C20 Scottsdale
1983 K2500 Sierra Classic Suburban 6.2
Instagram: C10sofOC
demian5 is offline   Reply With Quote
Old 04-19-2018, 11:30 AM   #8
un4gvn!
Registered User
 
un4gvn!'s Avatar
 
Join Date: Mar 2006
Location: Latrobe, Pa. 15650
Posts: 341
Re: Sagging master cylinder

Contact Captfab here on this web sight. He makes a bracket that eliminates the factory bracket that holds the booster to the firewall. My booster was close to the valve cover. By using his bracket, it lifts the booster away from the cover and it's more level. It also moves the booster closer to the firewall. By the look in your picture, it should move the booster back away from the carb.
un4gvn! is offline   Reply With Quote
Old 04-19-2018, 12:13 PM   #9
Bigdav160
Registered User
 
Bigdav160's Avatar
 
Join Date: Apr 2011
Location: Klein Texas
Posts: 3,852
Re: Sagging master cylinder

If you keep it "as-is" there are two additional support bars that you seem to be missing.
__________________
My Classics:
'72 K20 Suburban + '65 Dodge Town Wagon
'72 Corvette Roadster +'67 Corvette Roadster
'73 Z-28 Camaro
'63 Ford SWB Uni Pickup
'50 Ford Coupe
Bigdav160 is offline   Reply With Quote
Old 04-19-2018, 05:09 PM   #10
cleszkie
Registered User
 
cleszkie's Avatar
 
Join Date: Feb 2003
Location: Santa Ana, CA
Posts: 2,191
Re: Sagging master cylinder

Is that really how the Holly mounts to the manifold? I'm not used to seeing a carb in that sideways orientation. If it where turned 90 degrees it sure would provide more room for the booster. If all else fails, swap in a hydro-boost unit and get rid of the chunky booster.
cleszkie 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 06:51 AM.


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