Hard Brake Pedal? The Real Cause and Diagnostics - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat

1992-1999 Series I L27 (1992-1994 SE,SLE, SSE) & Series II L36 (1995-1999 SE, SSE, SLE) and common problems for the Series I and II L67 (all supercharged models 92-99) Including Olds 88's, Olds LSS's and Buick Lesabres Please use General Chat for non-mechanical issues, and Performance and Brainstorming for improvements.

Thread Tools Search this Thread
Old 05-03-2007, 10:38 AM   #1
Junior Member
Posts like a Ricer Type-R
Thread Starter
Join Date: Apr 2007
Location: New York
Posts: 13
Thanks: 0
Thanked 0 Times in 0 Posts
john_doe is on a distinguished road
Default Hard Brake Pedal? The Real Cause and Diagnostics

After one day my break pedal went to the floor for a second time last month (first time they bleed air out of the system and it worked ok for a week) i went to the shop. Lines and pads were checked everything was fine.
Diagnosis was "Master Cylinder Failure" and it was replaced...
Ever since my break was kinda hard but i didn't have time to get to the shop to show it to them. Plus it'* my first car and i don't really know who hard pedal should be.

But last night i was driving another car and had to drive mine right after it, and difference in force needed to be applied to the breaks nearly caused me an accident.

Please let me know what can be the problem and how can i single it out without getting ripped off... Because the master cylinder that was replaced was a year old and i don't really believe it could have been real problem.

Thank you
john_doe is offline   Reply With Quote
Old 05-03-2007, 03:07 PM   #2
Senior Member
True Car Nut
Join Date: Mar 2004
Location: Ames, Iowa
Posts: 3,066
Thanks: 0
Thanked 1 Time in 1 Post
bill buttermore is on a distinguished road

I wonder if your brake booster (the big, round vacuum can behind the master cylinder) has failed or has lost its vacuum supply. That would make the brakes much harder to operate. Check the hose that goes from the intake manifold to the booster to make sure it is connected and in good condition. Check to see if the diaphragm in the booster unit is good by disconnecting the vacuum supply hose at the booster with the engine idling. The idle should change drastically when you do this, as you are adding lots of un-metered air to the engine. If there is no change in the idle, that would suggest the diaphragm in the booster is ruptured. Also, check to make sure the vacuum supply hose is not internally blocked by placing your thumb over the end of the hose you disconnected with the engine running. You should feel a strong vacuum. If not, the hose is blocked.
bill buttermore is offline   Reply With Quote
Old 05-03-2007, 03:18 PM   #3
Retired Moderator
True Car Nut
Pearl_bonnie02's Avatar
Join Date: Sep 2006
Location: Northwest Indiana
Posts: 3,047
Thanks: 0
Thanked 0 Times in 0 Posts
Pearl_bonnie02 is on a distinguished road

I'd definetly look into it being the brake booster. My thunderbird'* brake booster was bad and I had the same problem. Once it was replaced, whala! Better brake pedal.
Pearl_bonnie02 is offline   Reply With Quote

Related Topics
Thread Thread Starter Forum Replies Last Post
2002 Olds Alero Hard Brake Pedal gmfan2014 Oldsmobile 7 12-10-2014 04:33 PM
hard brake pedal i-ross1 Buick 2 01-25-2011 09:49 PM
Brake pedal to the floor - no brake pressure milty 1992-1999 7 05-12-2008 10:13 AM
Brake pressure problem. Brake pedal travels to floor chilump 1992-1999 9 11-02-2006 11:37 AM
Gas pedal, brake pedal position younghelio 1992-1999 1 03-19-2004 12:10 AM

Thread Tools Search this Thread
Search this Thread:

Advanced Search

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

All times are GMT -4. The time now is 04:44 PM.

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.