GN and T-Type Performance Enthusiasts (GNTTYPE) Forums GN and T-Type Performance Enthusiasts (GNTTYPE) Forums
This is a general site search and does not include list archives.

Go Back   GN and T-Type Performance Enthusiasts (GNTTYPE) Forums > Technical Topics > Brakes

Reply
 
Thread Tools Display Modes
  #1  
Old 03-02-2013, 06:59 PM
Thejman Thejman is offline
 
Join Date: Mar 2013
Posts: 2
Thejman is on a distinguished road
Default Brake problem someone help please

I have an 86 GN. Recently I had an issue with a leaking wheel cylinder. So like anything else I replaced it. At the same time I decided to bleed the brakes all the way around to make sure there was no air in the system. I ended up replacing the front calipers do to the fact that the bleeders were ceased solid. So everything back together and I am ready to bleed. I was told gravity bleeding was the best way to get a good pedal. I started with the rears and a full res of dot 3 fluid. Well I got side tracked and forgot about the bleeders being open. The rears completely drained out and the res was empty. So I filled it and then bleed the brakes doing the old pump it twice and hold while I crack the bleeder. Doing all this with the key off. So I get an even flow of non air rated fluid . I figured they were all set but when I got in the care turned the key the pedal was really soft and the brake light was coming on. And of course the pump was coming on every time I applied the brakes. I figured there was air in the master so I bench bleed the master in the car to make sure no air was in it. Got some bubbles out. Then repeat bleeding this time with the key on. Still the same results . If anyone else has ever had this issue and can lead me in the rite direction. I would greatly appreciate it. I was thinking it might be the proportion valve. But I can hear a hissing at the master when I pump the brake "AIR" . Not sure i just want to figure this out so I can hit the track this year.
Reply With Quote
  #2  
Old 03-02-2013, 07:10 PM
Keller's Avatar
Keller Keller is offline
GNTTYPE Founder
 
Join Date: Jul 2004
Location: Missouri
Posts: 9,417
Keller is on a distinguished road
Exclamation Re: Brake problem someone help please

First, did you top off the master cylinder per the instructions on the top of the reservoir? i.e. After insuring all assist pressure was bled off by fully depressing the pedal with IGNITION OFF at least 10 times?

When you ran the Powermaster dry you probably got a lot of air into that as well.

I switched all my bleeder screws over to Russell "Speed Bleeders". I think this is the only way to do a one man bleed without getting air back into the system. Not absolutely necessary, but it really simplifies the process. Air really can't get back in from the bleed screws.

You may need to get the Powermaster itself free of air before you go much further. Also, you need to know that the system has fluid sucked into the assist side of the Powermaster when the ignition is on. And that fluid stays in it until the pedal is pumped at least 10 times with the ignition OFF. I would suggest doing a bleed (actively, not just "gravity") with the ignition off, and check the brakes after a full bleed of all four wheels. If that is not good enough, do the same with the ignition on. However, NEVER open the reservoir without turning the ignition off and pumping 10+ times with the key off.
__________________
Scott Keller - GNTTYPE Founder & Moderator

Last edited by Keller; 03-02-2013 at 07:13 PM.
Reply With Quote
  #3  
Old 03-02-2013, 11:12 PM
Thejman Thejman is offline
 
Join Date: Mar 2013
Posts: 2
Thejman is on a distinguished road
Default Re: Brake problem someone help please

Scott, thank you for your reply. I have not followed the instruction on the res cap. Only because I figured the system would bleed just the same as any other. Apparently I was wrong. I've tried to bleed the system about four times and I had a helper applying pressure to the brakes while I cracked the bleeders. I will run through it again following your instruction. I really don't know enough about this break system. Honestly this is the first break issue I have had . And it seems as if it was something I did because it worked perfect before I started replacing brake components . Once again thank you for the info Scott I will let you know how I make out.
Thanks Jamey
Reply With Quote
  #4  
Old 03-02-2013, 11:51 PM
Keller's Avatar
Keller Keller is offline
GNTTYPE Founder
 
Join Date: Jul 2004
Location: Missouri
Posts: 9,417
Keller is on a distinguished road
Lightbulb Re: Brake problem someone help please

Note that there is a LOT of articles on the Powermaster brake system on the site and in the forums. I'd suggesting reading all you can before you even touch it again. It is electro-hydraulic, and likely a bit different than others you may have seen before.
__________________
Scott Keller - GNTTYPE Founder & Moderator
Reply With Quote
  #5  
Old 03-29-2013, 11:54 PM
boostd87 boostd87 is offline
New Member
 
Join Date: Feb 2013
Posts: 10
boostd87 is on a distinguished road
Default Re: Brake problem someone help please

Thejman did you ever get your brakes figured out? I have the exact same thing going on right now. I seem to be doing everything right and still can't any pedal with the key on but have pedal with key off?????????????
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 05:19 AM.


This page maintained by: gnttype-webmaster@gnttype.org

The content, images, text and multimedia displayed and contributed by the members of the Grand National and T-Type Performance Enthusiasts Organization are Copyright ©1996-2005. No part, section, image, article or whole of this site may be reposted or redisplayed without permission of the author/contributor and/or the Grand National and T-Type Performance Enthusiasts Organization.

Powered by vBulletin® Version 3.7.3
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.