Ford Ranger Forum - Forums for Ford Ranger enthusiasts!

Go Back   Ford Ranger Forum - Forums for Ford Ranger enthusiasts! > > >
Forgot Password? Join Us!

Welcome to Ford Ranger Forum

Reply
 
Thread Tools Search this Thread

  #1  
Old 05-06-2014, 07:31 PM
themikster themikster is offline
Like the Forums
 
Join Date: Aug 2012
Posts: 44
Angry RPMs drop when brake applied; reverse hissing leak

Hey everyone, recently i have been noticing that when i come to a stop sign or red light and press the break normally that my Rpms will drop anywhere between 100-500 rpms and then when i hit the gas it kind of has a small jerk and the rpms jump back up and it drives fine. Does anyone know what this could be???

BTW: its a 2001 4x4 auto 4.0 v6 XLT




Another problem that has come up is when i put it in reverse (automatic) it almost sounds like the tranny is making a hisssing/vacuum leak? maybe a bad torque converter???

i have cleaned the IAC..




Any help would be more then appreciated, thanks!
__________________
2001 Ranger Xlt
4.0L
4x4 off road
Reply With Quote
  #2  
Old 05-06-2014, 07:47 PM
Ranger Truckin Ranger Truckin is offline
Light up everything
 
Join Date: Jan 2013
Posts: 5,215
Default

Aren't the RPMs suppose to go down when you brake
Reply With Quote
  #3  
Old 05-06-2014, 07:54 PM
themikster themikster is offline
Like the Forums
 
Join Date: Aug 2012
Posts: 44
Default

Not way below idle and act like it's going to die...
__________________
2001 Ranger Xlt
4.0L
4x4 off road
Reply With Quote
  #4  
Old 05-06-2014, 07:56 PM
Ranger Truckin Ranger Truckin is offline
Light up everything
 
Join Date: Jan 2013
Posts: 5,215
Default

Oh I didn't realize you meant so low
Reply With Quote
  #5  
Old 05-06-2014, 07:59 PM
07XL 07XL is offline
Socially awkward.
 
Join Date: Mar 2013
Posts: 6,327
Default

Are your brakes hard to push?
__________________
Blue 1998 Ford Ranger XLT stepside, single cab, 2.5L.
If you like LOLZ, click HERE for the best thread FRF has ever seen!
#BringbackHOI
Reply With Quote
  #6  
Old 05-06-2014, 08:04 PM
themikster themikster is offline
Like the Forums
 
Join Date: Aug 2012
Posts: 44
Default

Not extremely hard (for a 01 I think they feel normal) they stop me that's all I care about haha
__________________
2001 Ranger Xlt
4.0L
4x4 off road
Reply With Quote
  #7  
Old 05-06-2014, 08:13 PM
dangerranger94 dangerranger94 is offline
Ford Ranger Driver
 
Join Date: May 2012
Posts: 1,313
Default

Quote:
Originally Posted by themikster View Post
Not extremely hard (for a 01 I think they feel normal) they stop me that's all I care about haha
more then likely your brake booster is leaking
__________________
1996 f150 4x4 ext cab, Eddie Bauer edition, 5.8l auto, 3.55 gears and 31/10.5/15
My babe/DD-1995 2.3l 5speed 4x4, long bed, 4.10 open dif, "red rocket" 31/10.5/15s good years
Reply With Quote
  #8  
Old 05-06-2014, 08:15 PM
07XL 07XL is offline
Socially awkward.
 
Join Date: Mar 2013
Posts: 6,327
Default

Quote:
Originally Posted by dangerranger94 View Post
more then likely your brake booster is leaking
^^
Yep that's where I was going with this lol


That's also causing a vacuum leak which is dropping your idle.
__________________
Blue 1998 Ford Ranger XLT stepside, single cab, 2.5L.
If you like LOLZ, click HERE for the best thread FRF has ever seen!
#BringbackHOI
Reply With Quote
  #9  
Old 05-06-2014, 08:20 PM
themikster themikster is offline
Like the Forums
 
Join Date: Aug 2012
Posts: 44
Default

I will look into this more. How did you come up with the brake booster as an option? Btw: thanks for the suggestion!
__________________
2001 Ranger Xlt
4.0L
4x4 off road
Reply With Quote
  #10  
Old 05-06-2014, 08:23 PM
07XL 07XL is offline
Socially awkward.
 
Join Date: Mar 2013
Posts: 6,327
Default

It's a vacuum controlled part. Low idle is typically a vacuum leak, and you said it happened when the brakes were applied. So that makes me think it's the brake booster.
__________________
Blue 1998 Ford Ranger XLT stepside, single cab, 2.5L.
If you like LOLZ, click HERE for the best thread FRF has ever seen!
#BringbackHOI
Reply With Quote
  #11  
Old 05-06-2014, 08:26 PM
themikster themikster is offline
Like the Forums
 
Join Date: Aug 2012
Posts: 44
Default

Will look into this more.. Thanks for the input! Let me know if you think of anything else
__________________
2001 Ranger Xlt
4.0L
4x4 off road
Reply With Quote
  #12  
Old 05-06-2014, 08:32 PM
07XL 07XL is offline
Socially awkward.
 
Join Date: Mar 2013
Posts: 6,327
Default

You're welcome.
Let us know how it goes.
__________________
Blue 1998 Ford Ranger XLT stepside, single cab, 2.5L.
If you like LOLZ, click HERE for the best thread FRF has ever seen!
#BringbackHOI
Reply With Quote
  #13  
Old 05-06-2014, 08:34 PM
Fordzilla80 Fordzilla80 is offline
Welcome to FRF!
 
Join Date: Oct 2010
Posts: 8,954
Default Re: RPMs drop when brake applied; reverse hissing leak

When my brake booster took a shit, my idle sucked all the time, not just when I applied the brakes.

Does the truck idle like shit when you're sitting in park or neutral?
Reply With Quote
  #14  
Old 05-07-2014, 06:04 AM
themikster themikster is offline
Like the Forums
 
Join Date: Aug 2012
Posts: 44
Default

No it starts and idles like a champ
__________________
2001 Ranger Xlt
4.0L
4x4 off road
Reply With Quote
  #15  
Old 05-07-2014, 09:05 AM
01_ranger_4x4 01_ranger_4x4 is offline
OIF Veteran

 
Join Date: Feb 2010
Posts: 6,044
Default Re: RPMs drop when brake applied; reverse hissing leak

Brake booster
__________________
2001 Ranger 4x4 Stepside
-RCD Suspension lift
-33x12.5 BFG KM2's on Mickey Thomson classic locks
-4:56 gears
-Auburn gear LS
-James Duff traction bars
-Headers
-Flowmaster duals
-SCT X-Cal2 and some small exterior mods

http://www.cardomain.com/ride/2321189

2005 F-150 Lariat 4x4
-LED third brake light
-Weathertech floor liners
-Edge tuner
Reply With Quote
Reply

Tags
brake, drop, hissing, reverse, rpms

Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
RPMs drop low when coming to a stop? themikster 4.0 SOHC / 4.0 OHV Tech 8 10-11-2013 06:56 PM
any mods to make RPMS DROP FASTER? 2010 4-Cylinder Tech 18 02-23-2013 09:49 AM
Ranger 4x4 edge, RPMS drop at stop? daniel5625 4.0 SOHC / 4.0 OHV Tech 9 02-16-2013 06:17 PM
Braking RPMS drop rking4500 3.0 Vulcan Tech 5 12-22-2012 06:14 AM
Stalls when brakes are applied, and an oil leak. Ol' Paint 4-Cylinder Tech 7 07-13-2012 06:02 AM