hissing when braking - Hot Rod Forum : Hotrodders Bulletin Board
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> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 02-18-2012, 09:35 PM
cutthroatkid's Avatar
two cups of tea
 
Last wiki edit: Need more horsepower for my 305 Last photo:
Join Date: Jun 2009
Location: st.louis mo
Posts: 945
Wiki Edits: 2

Thanks: 19
Thanked 2 Times in 2 Posts
hissing when braking

Ok first off anybody who knows me on here knows I usually ask a ton of questions about my projects bit this is about my dd.Its a 2 nd gen dodge ram with the 360 awhile back the hvac started acting funny replaced every vac line I could find still no fix,next found out my plenum is leaking so I orderd the parts to fix but I haven't yet&today I go to run some errands&when I push my brakes I hear a hissing like when the booster goes bad.Ive checked the booster&cylinder &there ok.Now Im wondering could my leaking plenum gasket be causing these problems?When I bought my mustang it did the same thing hissing when applying brakes but booster was ok...ended up being a rusted out reservoir.So input?Could it be the plenum?

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 02-19-2012, 08:05 AM
T-bucket23's Avatar
Hotrodders.com Moderator
 
Last wiki edit: Engine basic condition - how to check Last photo:
Join Date: Aug 2005
Location: Massachusetts
Age: 57
Posts: 5,151
Wiki Edits: 26

Thanks: 7
Thanked 109 Times in 94 Posts
Bad booster
__________________
Artificial Intelligence is no match for Natural Stupidity



Chet
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 02-19-2012, 08:57 AM
cutthroatkid's Avatar
two cups of tea
 
Last wiki edit: Need more horsepower for my 305 Last photo:
Join Date: Jun 2009
Location: st.louis mo
Posts: 945
Wiki Edits: 2

Thanks: 19
Thanked 2 Times in 2 Posts
But Ive tested the booster&its holding vacuum.Ive turned it off&pumped brakes till hard held&started &it went slowly to ground&Ive started turned ofd&removed valve&heard the woosh.Like I said on my mustang it did the exact same thing&I replaced the booster&ot still did it ended up being a keak somewhere else that was causing the hiss@brakes&when I fixed that leak it fixed the hissing@brakes.Thats why Im wondering if its the plenum leak since it causes a vacuum leak in the crank case.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 02-19-2012, 07:55 PM
sbchevfreak's Avatar
Licenced Automotive Technician
 
Last photo:
Join Date: Feb 2004
Location: Land of big Easter eggs, Alberta
Age: 34
Posts: 1,604
Wiki Edits: 0

Thanks: 8
Thanked 9 Times in 9 Posts
Just because it hold vacuum, does not mean it won't leak when the brakes are applies. Put shortly, there is a valve system on the booster that allows atmospheric pressure into the rear chamber when the brakes are applied. This is the ``boosting`` effect. There is a vacuum and an atmospheric valve, and if you hear hissing when applying brakes, this valve assembly is shot.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 02-19-2012, 08:05 PM
cutthroatkid's Avatar
two cups of tea
 
Last wiki edit: Need more horsepower for my 305 Last photo:
Join Date: Jun 2009
Location: st.louis mo
Posts: 945
Wiki Edits: 2

Thanks: 19
Thanked 2 Times in 2 Posts
Quote:
Originally Posted by sbchevfreak
Just because it hold vacuum, does not mean it won't leak when the brakes are applies. Put shortly, there is a valve system on the booster that allows atmospheric pressure into the rear chamber when the brakes are applied. This is the ``boosting`` effect. There is a vacuum and an atmospheric valve, and if you hear hissing when applying brakes, this valve assembly is shot.
I got ya...not sure if this makes a difference or not but maybe my choice of words wasnt too good...its not reallyva hiss like a sucking or a leak more like when u push down on a kids bicycle air pump like shhw shhw sorry if thats a crappy explanation.
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply
Message:
Options

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.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
hissing noise after cranking timhollerbach96 Engine 7 02-27-2009 12:03 PM
hissing problem 18camaro Engine 3 03-06-2008 05:53 AM
Intermitent hissing sound dpjmw Engine 1 03-27-2005 10:37 PM
Hissing, Advance 66chevy2ss Engine 27 08-21-2002 08:50 AM
Hissing, Advance 66chevy2ss Engine 0 08-18-2002 05:03 PM


All times are GMT -6. The time now is 08:01 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.