vacuum leak or brake booster vacuum leak - Forums at Modded Mustangs
 
LinkBack Thread Tools
post #1 of 12 Old December 29th, 2013, 07:35 PM Thread Starter
Regular
 
Join Date: Sep 2011
Location: California
Posts: 122
 
iTrader: 0 reviews
vacuum leak or brake booster vacuum leak

Ive had a vaccuum leak for about a year already. I have replaced my intake manifold and gaskets with felpro gaskets and oem ford racing I/m.ive clamped all the hoses running off the cold air intake and the 1 f4om the pcv valve to valve cover. Car idles perfect and runs perfect. The vacuum leak sounds big real loud hissing so I cant understand how I would have no idle issues. Im starting to think it might be a brake booster vacuum leak. I do get a light hissing sound (seperate from initial leak hiss) when I step on the brake pedal. Any ideas?

04 gt. Mach 1 lip, grille delete, k&n cold air intake, 40 series flowmaster cat back, steeda tri ax short shifter
luv2shuv is offline  
Sponsored Links
Advertisement
 
post #2 of 12 Old December 29th, 2013, 07:39 PM
Poo tee weet?
 
Buddha's Avatar
 
Join Date: Jul 2012
Location: St.Paul, MN
Posts: 2,647
     
iTrader: 0 reviews
Our cars use hydoboost not vacuum boost.

Buddha is offline  
post #3 of 12 Old December 29th, 2013, 07:45 PM Thread Starter
Regular
 
Join Date: Sep 2011
Location: California
Posts: 122
 
iTrader: 0 reviews
Quote:
Originally Posted by Buddha View Post
Our cars use hydoboost not vacuum boost.
Damn. Im gonna have to read up on how the hydro boost system works.

04 gt. Mach 1 lip, grille delete, k&n cold air intake, 40 series flowmaster cat back, steeda tri ax short shifter
luv2shuv is offline  
post #4 of 12 Old December 29th, 2013, 07:57 PM
Poo tee weet?
 
Buddha's Avatar
 
Join Date: Jul 2012
Location: St.Paul, MN
Posts: 2,647
     
iTrader: 0 reviews
It takes hydraulic pressure from the power steering pump.

Buddha is offline  
post #5 of 12 Old December 29th, 2013, 08:13 PM Thread Starter
Regular
 
Join Date: Sep 2011
Location: California
Posts: 122
 
iTrader: 0 reviews
Quote:
Originally Posted by Buddha View Post
It takes hydraulic pressure from the power steering pump.
I see... so do you have any ideas about where I might want to check for a leak? I don't want to spend 150 $ bucks on a smoke test.

04 gt. Mach 1 lip, grille delete, k&n cold air intake, 40 series flowmaster cat back, steeda tri ax short shifter
luv2shuv is offline  
post #6 of 12 Old December 29th, 2013, 08:22 PM
Hardcore Enthusiast
 
black02's Avatar
 
Join Date: Jul 2011
Location: Newburgh Ny/Hartford Ct
Posts: 1,648
 
iTrader: 7 reviews
Quote:
Originally Posted by luv2shuv View Post
I see... so do you have any ideas about where I might want to check for a leak? I don't want to spend 150 $ bucks on a smoke test.
Spray starter fluid around by the lines or back of the motor if there's a leak it will burn the starter fluid you'll hear it


Sent from AutoGuide.com App
black02 is offline  
post #7 of 12 Old December 29th, 2013, 08:31 PM
Regular
 
Join Date: Jan 2011
Location: Indianapolis
Posts: 214
   
iTrader: 0 reviews
Like stated above, starting fluid around the vacuum leak will affect idle.

2000 GT

jbodell11 is offline  
post #8 of 12 Old December 29th, 2013, 08:47 PM
Enthusiast
 
46L281GT's Avatar
 
Join Date: Jan 2013
Location: Somerset, KY
Posts: 596
   
iTrader: 0 reviews
Are you using the stock PCV valve or an aftermarket valve


Sent from AutoGuide.com App

1999 Mustang GT 5 Speed Vert
Procharger P1SC @ 7 lbs
382/382 STD
Tuned by Chicken Hawk Motorsports

Supercharger Build Thread: http://www.moddedmustangs.com/forums...ld-thread.html
46L281GT is offline  
post #9 of 12 Old December 29th, 2013, 09:23 PM Thread Starter
Regular
 
Join Date: Sep 2011
Location: California
Posts: 122
 
iTrader: 0 reviews
Quote:
Originally Posted by black02 View Post
Spray starter fluid around by the lines or back of the motor if there's a leak it will burn the starter fluid you'll hear it


Sent from AutoGuide.com App
I've done that. I had minor leaks on the hoses that run fron the pcv and the ones that run from the air intake so I clamped them but the leak is still their....

---------- Post added at 06:19 PM ---------- Previous post was at 06:19 PM ----------

Quote:
Originally Posted by 46L281GT View Post
Are you using the stock PCV valve or an aftermarket valve


Sent from AutoGuide.com App
Motorcraft... I bought it from the dealer.

---------- Post added at 06:23 PM ---------- Previous post was at 06:19 PM ----------

Quote:
Originally Posted by jbodell11 View Post
Like stated above, starting fluid around the vacuum leak will affect idle.
The thing that trips me out is how loud the leak sounds but it doesn't affect the cars idle but the sound goes away then i hit the throttle and the rpms fly up but as soon as its back at idle rpms.... bam the hissing is back... my buddys bmw has a leak that's half as loud and his beemer turns off when its cold at idle.

04 gt. Mach 1 lip, grille delete, k&n cold air intake, 40 series flowmaster cat back, steeda tri ax short shifter
luv2shuv is offline  
post #10 of 12 Old December 29th, 2013, 10:10 PM
Enthusiast
 
46L281GT's Avatar
 
Join Date: Jan 2013
Location: Somerset, KY
Posts: 596
   
iTrader: 0 reviews
Oh okay then. The reason I asked is because I had bought a knock-off version and had a strange hissing/rattling sound and it was that crappy valve. I know they are supposed to rattle if you shake them, but this one was audible from within the cabin and definitely outside the vehicle. Just thought it might be the same issue that I had.
46L281GT is offline  
post #11 of 12 Old December 29th, 2013, 11:20 PM Thread Starter
Regular
 
Join Date: Sep 2011
Location: California
Posts: 122
 
iTrader: 0 reviews
Quote:
Originally Posted by 46L281GT View Post
Oh okay then. The reason I asked is because I had bought a knock-off version and had a strange hissing/rattling sound and it was that crappy valve. I know they are supposed to rattle if you shake them, but this one was audible from within the cabin and definitely outside the vehicle. Just thought it might be the same issue that I had.
A couple months ago I suspected of the pcv valve so I put the old one back on to see if it still hissed... and it did....

04 gt. Mach 1 lip, grille delete, k&n cold air intake, 40 series flowmaster cat back, steeda tri ax short shifter
luv2shuv is offline  
post #12 of 12 Old December 30th, 2013, 01:18 AM
Hardcore Enthusiast
 
07gtS197's Avatar
 
Join Date: Mar 2011
Location: Naples, Fl
Posts: 2,324
Blog Entries: 3
 
iTrader: 3 reviews
Get a vacuum guage and test the vacuum

07 gt Tungston gray
Roush (Airaid) Cai, GT500 Tb with BlowByRacing Adaptor Plate, UPR O/r X Pipe, M80's, Pypes Muffler Delete Axle Back, Sr Performance Adjustable Motor Mounts and Steeda Tri Ax Short Throw Shifter
07gtS197 is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Forums at Modded Mustangs forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
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:
OR

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.



Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



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

 
For the best viewing experience please update your browser to Google Chrome