Converted to 12" Disk All Around..Problem - Team Camaro Tech
Brakes, Suspension & Steering Conversion questions, Steering & Handling

Reply
 
LinkBack Thread Tools Display Modes
post #1 of 18 (permalink) Old Sep 17th, 09, 04:16 PM Thread Starter
Senior Tech
JB
 
Join Date: May 2008
Location: Palm City, FL
Posts: 306
Converted to 12" Disk All Around..Problem

I converted my a 67 Camaro to 4 wheel 12" disk brakes from a 98 LS1 Camaro (dual pistons in front), I Used stock lines with metric adapters into the caliper lines; a 79 TA 4-wheel disk master cylinder and a Jegs adjustable proportioning/distribution valve. I had the system professionally bled so there is no air. I have the matched short Master Cyl plunger and short Master Cyl puck set up (Power Brakes).. the brakes don't gradually grab, but seem to grab all at once near the bottom of the pedal stroke. Not impressive as they should be. They're very stale. I adjusted the valve to all the way closed and mostly open and don't feel a huge difference moving the car around the driveway. One thought is that the lines from the MC to the Porp Valve are 5/16".. I'm wondering if 3/8" would make a huge difference??

Anyone got any suggestions on trying to figure out why, so I can improve braking to what it should be??
69RSMAN is offline  
Sponsored Links
Advertisement
 
post #2 of 18 (permalink) Old Sep 17th, 09, 04:50 PM Thread Starter
Senior Tech
JB
 
Join Date: May 2008
Location: Palm City, FL
Posts: 306
Re: Converted to 12" Disk All Around..Problem

oops I meant 3/16 line from 1/8
69RSMAN is offline  
post #3 of 18 (permalink) Old Sep 17th, 09, 05:07 PM
Gold Lifetime Member
Andrew
 
Andrew69's Avatar
 
Join Date: Nov 2002
Location: Greenwood, SC
Posts: 5,562
Re: Converted to 12" Disk All Around..Problem

The LS1 brakes need a master cylinder no larger than a 1" bore, like from a 70's era Corvette. What is the bore diameter of the 79 TA?
Are you sure all the air is out of the lines? Was the master cylinder bench bled?

Skunk Works
302DZ, M22W Muncie, GV overdrive,12-Bolt Rear 3.73
Some photos:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Member # 159
Andrew69 is offline  
 
post #4 of 18 (permalink) Old Sep 17th, 09, 05:51 PM Thread Starter
Senior Tech
JB
 
Join Date: May 2008
Location: Palm City, FL
Posts: 306
Re: Converted to 12" Disk All Around..Problem

Yes, system bled with machine and MC bench bled.. TA MC has 1-1/8 bore. I thought bigger was better for volume??
69RSMAN is offline  
post #5 of 18 (permalink) Old Sep 17th, 09, 05:59 PM
Gold Lifetime Member
Andrew
 
Andrew69's Avatar
 
Join Date: Nov 2002
Location: Greenwood, SC
Posts: 5,562
Re: Converted to 12" Disk All Around..Problem

Bigger gives you more volume but smaller gives you more power. The LS1 Camaros had master cylinders with a 1" bore and piston, you need to duplicate that with your car. These guys sell conversion kits using Corvette parts and their M/C has the 1" bore. http://www.touring-classics.com/accessories.htm
Are you running the vacuum assisted brake booster?

Skunk Works
302DZ, M22W Muncie, GV overdrive,12-Bolt Rear 3.73
Some photos:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Member # 159
Andrew69 is offline  
post #6 of 18 (permalink) Old Sep 17th, 09, 06:13 PM Thread Starter
Senior Tech
JB
 
Join Date: May 2008
Location: Palm City, FL
Posts: 306
Re: Converted to 12" Disk All Around..Problem

yes, 11" from a Chevelle
69RSMAN is offline  
post #7 of 18 (permalink) Old Sep 17th, 09, 06:16 PM Thread Starter
Senior Tech
JB
 
Join Date: May 2008
Location: Palm City, FL
Posts: 306
Re: Converted to 12" Disk All Around..Problem

Do you know if the Vette MC has the shallow hole for plunger rod or deeper hole?
69RSMAN is offline  
post #8 of 18 (permalink) Old Sep 17th, 09, 06:59 PM
Gold Lifetime Member
Don
 
Join Date: Jan 2005
Location: 2 Dog Town in West Texas
Posts: 11,152
Re: Converted to 12" Disk All Around..Problem

Quote:
Originally Posted by 69RSMAN View Post
Do you know if the Vette MC has the shallow hole for plunger rod or deeper hole?
I just got the 4 wheel disc M/c from Matts, it off a 69 Vette I was told, has the stock 69 PB plunger depth, not sure what you call deep or shallow, it was 1 3/4" deep .

Just did a rear drum to disc conversion.

Don
TC # 349
Zdld17:69 Z/RS,306, NOR141111, 9N554XXX, 12A, X3G, 59/59,723, AFR 195,CCC282/290HR, TKO 600, BU1122B1E Owner since Dec 1968

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
zdld17 is offline  
post #9 of 18 (permalink) Old Sep 17th, 09, 07:07 PM Thread Starter
Senior Tech
JB
 
Join Date: May 2008
Location: Palm City, FL
Posts: 306
Re: Converted to 12" Disk All Around..Problem

The rod hole depth on mine is real shallow. Maybe 3/4" or so. The deep one is 1.750" deep. I do have both rods available, so I can use what I can find. I may try the 1" bore vette M/C since I've been seeing it mentioned and have researched it further. Is the power brake MC 1-1/8 and manual 1"? I've been seeing this mentioned in a couple of articles..

What does the 69 one measure?
69RSMAN is offline  
post #10 of 18 (permalink) Old Sep 17th, 09, 07:08 PM Thread Starter
Senior Tech
JB
 
Join Date: May 2008
Location: Palm City, FL
Posts: 306
Re: Converted to 12" Disk All Around..Problem

I missed again. You said 1-3/4
69RSMAN is offline  
post #11 of 18 (permalink) Old Sep 17th, 09, 07:09 PM Thread Starter
Senior Tech
JB
 
Join Date: May 2008
Location: Palm City, FL
Posts: 306
Re: Converted to 12" Disk All Around..Problem

Do you know if the 69 bore dia for PB was 1-1/8 or 1"?
69RSMAN is offline  
post #12 of 18 (permalink) Old Sep 17th, 09, 07:42 PM
Senior Tech
Al
 
Join Date: Nov 2002
Location: Vancouver, USA
Posts: 10,511
Re: Converted to 12" Disk All Around..Problem

The 69 factory power disc/drum used a 1 1/8 bore MC. The 1969 single piston calipers had huge pistons. Even though your LS1 brakes have 2 pistons (fronts) the total area of the two is still less than the area of the single piston 69 caliper. The smaller bore MC is needed to create enough line pressure to operate your smallish piston calipers. With your current setup you should have very little pedal travel, and not enough line pressure to operate the brakes effectively. If you have a fair amount of pedal travel I'd suspect air in the system.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
BPOS is offline  
post #13 of 18 (permalink) Old Sep 17th, 09, 08:22 PM Thread Starter
Senior Tech
JB
 
Join Date: May 2008
Location: Palm City, FL
Posts: 306
Re: Converted to 12" Disk All Around..Problem

What Power Brake MC is 1" bore that'll work for me? Isn't the Vette Power MC bore 1-1/8" ?
69RSMAN is offline  
post #14 of 18 (permalink) Old Sep 17th, 09, 08:23 PM Thread Starter
Senior Tech
JB
 
Join Date: May 2008
Location: Palm City, FL
Posts: 306
Re: Converted to 12" Disk All Around..Problem

and yes, I have quite a bit of travel in the brakes..maybe since the system is new, there's hidden air in the prop valve or still in the MC
69RSMAN is offline  
post #15 of 18 (permalink) Old Sep 18th, 09, 08:58 AM Thread Starter
Senior Tech
JB
 
Join Date: May 2008
Location: Palm City, FL
Posts: 306
Re: Converted to 12" Disk All Around..Problem

I re-checked. I do have a 70 vete MC already installed for PB...
69RSMAN 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