Hard brake pedal before starting - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep Grand Cherokee & Commander Forums > WK2 Grand Cherokee Forum > Hard brake pedal before starting

Ruffstuff Axle Simple Swap Kit!Even Better Heim Pricing! From RuffstuffToxic Brakes - 3000 PSI Braided Stainless Steel Brake Line

Reply
Unread 08-20-2013, 08:52 PM   #1
bikerbill7
Registered User
 
Join Date: Nov 2006
Location: Naperville, IL
Posts: 42
Hard brake pedal before starting

I've seen the thread regarding a hard brake pedal while driving. But I occasionally experience a hard brake pedal BEFORE starting my 2011 Limited 5.7. The brake pedal is never hard while driving, and it's only hard before starting after the vehicle has sat in the garage for a couple / few days. After the motor starts, the pedal goes down to normal "power-brake" feel. Any thoughts as to what's going on?

bikerbill7 is offline   Reply With Quote
Unread 08-21-2013, 05:45 AM   #2
Gran_Paradiso
2014 Overland HEMI
 
Gran_Paradiso's Avatar
2014 WK 
 
Join Date: Jul 2011
Location: Seven Fields, Pennsylvania
Posts: 445
I have the same thing happen. Been reading on this forum its common and normal. This is the first vehicle I've owned that has done this though.
Gran_Paradiso is offline   Reply With Quote
Unread 08-21-2013, 06:13 AM   #3
Jpiwonski
Registered User
2011 WK 
 
Join Date: Apr 2013
Location: Simsbury, Ct
Posts: 99
My 11 does it every so often as well.
Jpiwonski is offline   Reply With Quote
Unread 08-21-2013, 06:17 AM   #4
ColdCase
My Reality Check Bounced
 
ColdCase's Avatar
2011 WK 
 
Join Date: Sep 2009
Location: New England
Posts: 3,736
My 2011 pedal is hard all the time before starting.
__________________
2011 Grand Cherokee Overland V8, 2009 Liberty Rocky Mt V6, 2000 Grand Cherokee Laredo I6, 1979 CJ7 I6 Quadratrac
ColdCase is offline   Reply With Quote
Unread 08-21-2013, 06:42 AM   #5
jacko15
Registered User
2014 WK 
 
Join Date: Oct 2008
Location: Pennsylvania's North Shore
Posts: 789
Quote:
Originally Posted by ColdCase View Post
My 2011 pedal is hard all the time before starting.
My '14 is the same way. I believe it is normal.
__________________
Hers: 2008 Jeep Compass Sport
Mine: 2014 Jeep Grand Cherokee Overland V/6 ORA II
Michelin LTX M/S 2's
jacko15 is offline   Reply With Quote
Unread 08-21-2013, 06:44 AM   #6
tjkj2002
Registered User
2002 KJ Liberty 
 
Join Date: Dec 2009
Location: Colorado
Posts: 8,032
Quote:
Originally Posted by bikerbill7 View Post
I've seen the thread regarding a hard brake pedal while driving. But I occasionally experience a hard brake pedal BEFORE starting my 2011 Limited 5.7. The brake pedal is never hard while driving, and it's only hard before starting after the vehicle has sat in the garage for a couple / few days. After the motor starts, the pedal goes down to normal "power-brake" feel. Any thoughts as to what's going on?
Normal since you do not have any vacuum assist with the engine off.

Start the engine,run for a 30 seconds,turn off engine.Pump the brake pedal,you will notice it gets harder as the vacuum in the booster is drained.
__________________
'02 Liberty sitting on 35" tires,HP44,RockJock60,and AtlasII t-case
tjkj2002 is offline   Reply With Quote
Unread 08-21-2013, 09:06 AM   #7
bikerbill7
Registered User
 
Join Date: Nov 2006
Location: Naperville, IL
Posts: 42
I understand the vacuum issue, but this is the first vehicle I've owned that has done this in my 40 years of driving. Thus the question, why?
bikerbill7 is offline   Reply With Quote
Unread 08-21-2013, 11:07 AM   #8
ColdCase
My Reality Check Bounced
 
ColdCase's Avatar
2011 WK 
 
Join Date: Sep 2009
Location: New England
Posts: 3,736
A hard pedal is typical (for most brands) when all or most of the vacuum has been released from the booster before the start. There is a check valve that retains booster vacuum after shutoff, but these systems leak a bit regardless. You will see similar comments on other forums, typically BMW. From vehicle to vehicle, the vacuum leaks away at different rates, but it does leak over time. If you have a bad check valve, it may release the vacuum sooner than later.


My 2000 Jeep WJ had a hard pedal before start, I think also the 2006 Ram, but not as firm as the WK2.. my 2009KK not so much. I haven't thought of it as being unusual, but the feel may be different than other makes and models.
__________________
2011 Grand Cherokee Overland V8, 2009 Liberty Rocky Mt V6, 2000 Grand Cherokee Laredo I6, 1979 CJ7 I6 Quadratrac
ColdCase is offline   Reply With Quote
Unread 08-21-2013, 03:17 PM   #9
steveinaz
Registered User
2011 WK 
 
Join Date: Jun 2011
Location: Javelina, Arizona
Posts: 155
My 2011 laredo has done this from day 1, it's a non-issue, looking for a solution.
__________________
2011 Grand Cherokee Laredo 4X4
3.6L V-6 with Selec-Terrain
Off-Road Adventure package
Tow package
steveinaz is offline   Reply With Quote
Unread 08-21-2013, 06:50 PM   #10
BobsWK2
Registered User
2014 WK 
 
Join Date: Nov 2011
Location: West Coast
Posts: 387
Quote:
Originally Posted by ColdCase View Post
A hard pedal is typical (for most brands) when all or most of the vacuum has been released from the booster before the start. There is a check valve that retains booster vacuum after shutoff, but these systems leak a bit regardless. You will see similar comments on other forums, typically BMW. From vehicle to vehicle, the vacuum leaks away at different rates, but it does leak over time. If you have a bad check valve, it may release the vacuum sooner than later.
My 2014 sometimes (while parked) retains the vacuum for 5-6 days, othertimes it loses vacuum overnight. Doesn't say much for quality since it isn't consistant.
__________________
2014 Summit 4X4 V8
BobsWK2 is offline   Reply With Quote




Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.