69 Brake Booster Pins - Team Camaro Tech
Brakes, Suspension & Steering Conversion questions, Steering & Handling

 
LinkBack Thread Tools Display Modes
post #1 of 4 (permalink) Old Jun 9th, 19, 09:38 PM Thread Starter
Gold Lifetime Member
Phil
 
Join Date: Jul 2005
Location: South Carolina
Posts: 175
69 Brake Booster Pins

I bought a reproduction power disc brake booster for my 69 Camaro. It came with 2 booster to master cylinder piston pins. One short and one long. The reproduction 309 master cylinder came with a spud, stub or extension (whatever it's called) in the piston hole. The short pin and the stub measures the same length as the long pin without the stub. Why would this booster kit come with a long pin and a short pin? Which should I use, long pin without spud or short pin with the spud? Please look at attached picture.
Attached Thumbnails
Click image for larger version

Name:	IMG_20190609_230216880.jpg
Views:	17
Size:	433.5 KB
ID:	227535  
Bigfish45 is offline  
Sponsored Links
Advertisement
 
post #2 of 4 (permalink) Old Jun 9th, 19, 10:06 PM
Gold Lifetime Member
Beth
 
Join Date: Mar 2018
Location: Nashville TN
Posts: 483
Re: 69 Brake Booster Pins

Quote:
Originally Posted by Bigfish45 View Post
I bought a reproduction power disc brake booster for my 69 Camaro. It came with 2 booster to master cylinder piston pins. One short and one long. The reproduction 309 master cylinder came with a spud, stub or extension (whatever it's called) in the piston hole. The short pin and the stub measures the same length as the long pin without the stub. Why would this booster kit come with a long pin and a short pin? Which should I use, long pin without spud or short pin with the spud? Please look at attached picture.
This should help :

https://techtalk.mpbrakes.com/how-to...r-cylinder-gap

68 Camaro convertible, 6.0 LQ4 with LS3 heads, Vintage Air, 750 street demon carb, eddy perf rpm, GM hot cam, Hooker headers, 4L80e, 12 bolt, 3.55 gears
NashvilleCat is offline  
post #3 of 4 (permalink) Old Jun 10th, 19, 01:01 AM
Senior Tech
Garth
 
Join Date: Jul 2008
Location: I 5
Posts: 6,813
Re: 69 Brake Booster Pins

Just use the long rod (pin). The booster came with both long and short, depending on what MC is being used. The MC came with a "spud", to be used if the booster has a short rod, or to remove the spud if the booster came with a long rod. Like you say, both set-ups are the same length.

  • '68 RS, AA, 749, L30, M(uncie)20 (originally a 3spd), 15yr backburner resto........
Garfields Maro is online now  
 
post #4 of 4 (permalink) Old Jun 10th, 19, 09:04 AM Thread Starter
Gold Lifetime Member
Phil
 
Join Date: Jul 2005
Location: South Carolina
Posts: 175
Re: 69 Brake Booster Pins

Well I've ran into an issue. With the short rod inserted into the booster and the "spud" inserted in the master cylinder, the mounting flange of the master cylinder will not mate with the mounting surface of the booster. If I push the master cylinder against the booster flange, I can feel the piston in the master cylinder depressing. If I installed it like that, I would have locked down brakes from the get go. The master cylinder likes about .100" from seating to the booster. I have ordered one of the booster pin gauges and it's obvious I will need to make an adjustment. Instead of trying to shorten the booster pin and get the correct radius back on it, I think I will probably have the "spud" machined down on it's non-concave side. I've read that there needs to be .020" clearance between the master cylinder piston seat and the booster rod. I would think that with today's CNC machining and precision, aftermarket parts manufacturers would have everything exact in dimensions. It's obvious the mismatch between my booster and master cylinder is either a manufacturing error or their blueprints are wrong to begin with. It seems like most of the time with reproduction parts, I have to "make" them fit or work correctly.
Attached Thumbnails
Click image for larger version

Name:	200-13-big.jpg
Views:	13
Size:	55.2 KB
ID:	227543  
Bigfish45 is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Team Camaro Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address.
NOTE we receive a lot of registrations with bad email addresses. IF you do not receive your confirmation email you will not be able to post. contact support and we will try and help.
Be sure you enter a valid email address and check your spam folder as well.



Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may 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
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome