Hot Rod Forum : Hotrodders Bulletin Board - Reply to Topic
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Suspension - Brakes - Steering> 11" rear drums lock first.
User Name
Password
lost password?   |   register now

Thread: 11" rear drums lock first. Reply to Thread
Title:
  
Message:
Trackback:
Send Trackbacks to (Separate multiple URLs with spaces) :

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
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 for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Additional Options
Miscellaneous Options

Topic Review (Newest First)
09-08-2011 11:14 AM
ss396si I was checking out the adj prop valves on summit and jegs. All these valves on the market come with 3/16, Would it be a good idea to change from a 1/4 in to 3/16 line??
09-06-2011 03:20 PM
OneMoreTime Just needs to be where you can access it easily to make your adjustments. Start out on gravel and then proceed to higher speeds until you are satisfied. the goal is to be able to dynamite the brakes at freeway speeds without lockup on one end or another so the car stays straight and controllable in a panic situation..

Sam
09-06-2011 03:15 PM
ss396si
Quote:
Originally Posted by OneMoreTime
The factory prop valve is calibrated for the original brake setup and works fine on a factory car. when we change the brake setup as you have done then the old calibration does not work and then you need the adjustable prop valve..

Sam
How close does the adjustable prop valve need to be to the distribution block? I would need to buy extra steel lines for this install as well?
09-06-2011 02:54 PM
OneMoreTime The factory prop valve is calibrated for the original brake setup and works fine on a factory car. when we change the brake setup as you have done then the old calibration does not work and then you need the adjustable prop valve..

Sam
09-06-2011 01:28 PM
ss396si It's a 69 chevelle, disc/drum setup. The prop valve, Mc is new as well as the 11" booster, all parts not original. The prop valve is one of those big brass types from original parts group.
My problem occurred when I installed 11" rear brake (9.5" drums origanily) I got off a 76 monte carlo.
09-06-2011 07:12 AM
cobalt327
Quote:
Originally Posted by ss396si
What kind of adjustable distribution block do I need? The kind that replaces my excisting prop block or the one that goes behind it?
It will help immensely if you would give a complete run-down of just what you now have. Drum/drum, disc/drum, original master cylinder or aftermarket or from another vehicle, is it a fast take-up type, what type distribution block do you have, as in does it contain a prop valve (i.e. is it a combo valve), is the m/c above or below the brake cylinders, do you have any residual pressure valving installed?

If it's a combo valve w/a functional prop valve:

If you don't like the front/rear balance, and you were to add an adjustable proportioning valve to the existing combo valve, you would in effect be adding a prop valve to a prop valve. In your case (having too much rear brake), this wouldn't be an issue unless other changes to the brakes or weight distribution, etc. were to be made that required there to be more rear brake pressure than the existing combo prop valve allows.

If you add an adjustable prop to the existing prop, you would not be able to bias the rear brakes to have any more pressure to them than the existing setting of the existing prop valve- all you could do would be to take pressure away from them. But as I said, in your case this isn't so much of an issue.

Should you want to disable the combo valve prop function:

On most GM combo valves, you can disable the combo valve's prop valve by unscrewing the fitting from the combo valve that has the rear brake line coming from it, then remove the (rubber or spring loaded metal) valve inside the body, then reattach the fitting.



So- in your case- I would keep the existing combo/distribution block and simply plumb in an adjustable prop valve aft of the existing block. Should the need ever arise that you needed more rear brake bias than the existing combo prop valve allows, you will need to disable it. I hope I didn't confuse you too much.
09-06-2011 07:10 AM
Frisco
Quote:
Originally Posted by ss396si
What kind of adjustable distribution block do I need? The kind that replaces my excisting prop block or the one that goes behind it?
This kind. Left click on the image for a larger view. Available at most aftermarket suppliers. I like Speedway for my source. Use the Wilwood or the Speedway brand.

This unit installs after the master cylinder in the rear line. It can reduce the rear line pressure up to 60%. Turning the adjustable valve all the way clockwise is wide open. (Reverse from what you would think).
09-06-2011 06:35 AM
ss396si What kind of adjustable distribution block do I need? The kind that replaces my excisting prop block or the one that goes behind it?
09-03-2011 08:25 PM
OneMoreTime Yes..........

Sam
09-03-2011 06:42 PM
ss396si
11" rear drums lock first.

Driving on the service road, I decided to test my brakes and my 11" rear drums locked before my front disc. My chevelle originally had 9.5" drums in the back. Do you think I need an adjustable pro valve?

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


All times are GMT -6. The time now is 07:39 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.