Brake booster install
 

70 GMC C20

Never played w/a booster before.

Bought a new one...
https://i.imgur.com/3dAY4xJ.jpg
https://i.imgur.com/isG6XYr.jpg

Old booster rod length is 8 3/4" from housing to end of rod.
New rod was to long....
https://i.imgur.com/Gw2K3K7.jpg

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.

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!

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!

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

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

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

Re: Brake booster install
 

I surely am interested in the difference between the firewall to the master cylinder overall length differences.

Re: Brake booster install
 

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.


I'll get you the measurements tomorrow.

Re: Brake booster install
 

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.

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