News: Putting FUN and FRIENDLINESS, FIRST into owning and learning about AMC small bodied cars, primarily Eagles, Spirits and Concords as well as vehicles built in AMC's Mexican subsidiary, VAM.

The AMC Eaglepedia can now be accessed using the buttons found below  This is a comprehensive ever growing archive of information, tips, diagrams, manuals, etc. for the AMC Eagle and other small bodied AMC cars. 

Also a button is now available for our Face Book Group page.


Welcome to the AMC Eagles Nest.  A new site under "old" management -- so welcome to your new home for everything related to AMC Eagles, Spirits and Concords along with opportunities to interact with other AMC'ers.  This site will soon be evolving to look different than it has and we will be incorporating new features we hope you will find useful, entertaining and expand your AMC horizons.

You can now promote your topics at your favorite social media site by clicking on the appropriate icon (top upper right of the page) while viewing the topic you wish to promote.


  • March 28, 2024, 12:28:45 PM

Login with username, password and session length

Author Topic: EDIT: Mysterious power brake issue  (Read 1200 times)

0 Members and 1 Guest are viewing this topic.

Offline zeebo76

  • Eagle
  • **
  • Posts: 47
  • Thumbs Up 6
EDIT: Mysterious power brake issue
« on: September 20, 2019, 11:44:41 PM »
Since my previous Q&A wasn’t getting any bites, I figured I’d just edit my new question over it.

I’ve got an ‘86 Wagon the power (vacuum) brakes. About half of the time I start her up they feel fine from the get-go, but about half the time I’ll get an annoying little issue.

Until I actually get to driving (i.e. until I leave my driveway, the parking lot, whatever slow area I’m in) the brake pedal has absolutely no resistance until I get about 3/4 of the way down and then BANG, they just about lock up.  I’ve gotten mindful enough of it that I can manage driving it with this problem for as short a time as it lasts, but I still want to fix it.

Like I said, it only happens about half the time, and when it does happen it only lasts from the time I crank her to the time that I get her out onto the open road, maybe about 30 seconds max.  From that point on the brakes feel normal and don’t develop that issue again until I shut her off, leave for a while, and come back to potentially start the whole process over again.

I’ve done a little searching and a little looking at the booster and master cylinder but still have no leads.  Any ideas?
« Last Edit: September 24, 2019, 02:56:36 AM by zeebo76 »

Offline Canoe

  • Eagle Sundaancer
  • ******
  • Posts: 1150
  • Thumbs Up 54
Re: EDIT: Mysterious power brake issue
« Reply #1 on: October 17, 2019, 11:07:28 PM »
Grasping at straws...
Wrong vacuum source for the booster?
Bleed the master-cylinder?

Offline DAVE

  • Eagle DL
  • ***
  • Posts: 217
  • Thumbs Up 8
Re: EDIT: Mysterious power brake issue
« Reply #2 on: October 18, 2019, 10:46:41 AM »
check for leaks brake fluid will cause lockup also flash rust

 

SMF spam blocked by CleanTalk