User Tag List

Reply
 
Thread Tools Rate Thread Display Modes
Old 10-16-2019, 04:08 PM #1
Good351's Avatar
Good351 Good351 is offline
Member
 
Join Date: Aug 2009
Location: St. Paul, MN
Posts: 53
Good351 is on a distinguished road
Good351 Good351 is offline
Member
Good351's Avatar
 
Join Date: Aug 2009
Location: St. Paul, MN
Posts: 53
Good351 is on a distinguished road
brake pedal sometimes goes mushy

Hello everyone!
I've recently had the brake pedal on my 03 Runner sometimes go mushy.. Like it takes a lot of travel to start engaging the brakes. It's probably 50/50 now working correctly or requiring extra travel. Also, if it does require extra travel, I can then "pump up" the pedal and force it to act normal.

I've read a few posts on checking the brake booster pump.. How does one check this or listen if it is working?

Rear brakes are 2 years old, fronts just over a year (all new parts).
__________________
Current: 03 V8 4Runner. FJ front springs, Bilstein shocks. 236k miles.

Sold: 08 Double Cab TRD Off Road Tacoma. Not stock.

Bought back by Toyota: 99 Tacoma TRD Off Road. Stock. Crushed.
Good351 is offline   Reply With QuoteReply With Quote
Old 10-16-2019, 04:46 PM #2
That_Titanium_4RNR's Avatar
That_Titanium_4RNR That_Titanium_4RNR is offline
Member
 
Join Date: Dec 2018
Location: NC
Age: 22
Posts: 596
Real Name: Michael
That_Titanium_4RNR is a jewel in the rough That_Titanium_4RNR is a jewel in the rough That_Titanium_4RNR is a jewel in the rough
MY GARAGE
That_Titanium_4RNR That_Titanium_4RNR is offline
Member
That_Titanium_4RNR's Avatar
 
Join Date: Dec 2018
Location: NC
Age: 22
Posts: 596
Real Name: Michael
That_Titanium_4RNR is a jewel in the rough That_Titanium_4RNR is a jewel in the rough That_Titanium_4RNR is a jewel in the rough
MY GARAGE
Quote:
Originally Posted by Good351 View Post
Hello everyone!
I've recently had the brake pedal on my 03 Runner sometimes go mushy.. Like it takes a lot of travel to start engaging the brakes. It's probably 50/50 now working correctly or requiring extra travel. Also, if it does require extra travel, I can then "pump up" the pedal and force it to act normal.

I've read a few posts on checking the brake booster pump.. How does one check this or listen if it is working?

Rear brakes are 2 years old, fronts just over a year (all new parts).
Start by getting your brake fluid flushed and bled
__________________
Titanium Metallic 2006 Limited 4WD V8 | 5th Gen Brake Swap | Slyfox AIP Bypass | TPMS Bypass | Fog Light Mod | Everything else is in the Build Thread
That_Titanium_4RNR is offline   Reply With QuoteReply With Quote
Old 10-16-2019, 05:12 PM #3
Good351's Avatar
Good351 Good351 is offline
Member
 
Join Date: Aug 2009
Location: St. Paul, MN
Posts: 53
Good351 is on a distinguished road
Good351 Good351 is offline
Member
Good351's Avatar
 
Join Date: Aug 2009
Location: St. Paul, MN
Posts: 53
Good351 is on a distinguished road
Quote:
Originally Posted by That_Titanium_4RNR View Post
Start by getting your brake fluid flushed and bled
Oh, I should have stated that the brakes were bled about 2 months ago when a faulty caliper was replaced under warranty.
__________________
Current: 03 V8 4Runner. FJ front springs, Bilstein shocks. 236k miles.

Sold: 08 Double Cab TRD Off Road Tacoma. Not stock.

Bought back by Toyota: 99 Tacoma TRD Off Road. Stock. Crushed.
Good351 is offline   Reply With QuoteReply With Quote
Old 10-16-2019, 08:35 PM #4
That_Titanium_4RNR's Avatar
That_Titanium_4RNR That_Titanium_4RNR is offline
Member
 
Join Date: Dec 2018
Location: NC
Age: 22
Posts: 596
Real Name: Michael
That_Titanium_4RNR is a jewel in the rough That_Titanium_4RNR is a jewel in the rough That_Titanium_4RNR is a jewel in the rough
MY GARAGE
That_Titanium_4RNR That_Titanium_4RNR is offline
Member
That_Titanium_4RNR's Avatar
 
Join Date: Dec 2018
Location: NC
Age: 22
Posts: 596
Real Name: Michael
That_Titanium_4RNR is a jewel in the rough That_Titanium_4RNR is a jewel in the rough That_Titanium_4RNR is a jewel in the rough
MY GARAGE
Quote:
Originally Posted by Good351 View Post
Oh, I should have stated that the brakes were bled about 2 months ago when a faulty caliper was replaced under warranty.
Next step is turn the car on and then open the hood. Have someone get close to the master cylinder while you press the brakes. They should hear an electric buzzing type sound when you depress the brakes. It should happen every time the brakes are depressed I believe.
__________________
Titanium Metallic 2006 Limited 4WD V8 | 5th Gen Brake Swap | Slyfox AIP Bypass | TPMS Bypass | Fog Light Mod | Everything else is in the Build Thread
That_Titanium_4RNR is offline   Reply With QuoteReply With Quote
Old 10-16-2019, 09:13 PM #5
95supra 95supra is offline
Member
 
Join Date: May 2014
Location: ct
Posts: 80
95supra is on a distinguished road
95supra 95supra is offline
Member
 
Join Date: May 2014
Location: ct
Posts: 80
95supra is on a distinguished road
could be a stuck caliper or possibly a front wheel bearing. check both front wheel bearings for excessive play. this with cause the brake pedal to have too much travel at times.
95supra is offline   Reply With QuoteReply With Quote
Old 10-16-2019, 09:21 PM #6
AuSeeker AuSeeker is online now
Senior Member
 
Join Date: Nov 2016
Location: Bluffton S.C.
Posts: 2,804
Real Name: Skip
AuSeeker is a name known to all AuSeeker is a name known to all AuSeeker is a name known to all AuSeeker is a name known to all AuSeeker is a name known to all AuSeeker is a name known to all
AuSeeker AuSeeker is online now
Senior Member
 
Join Date: Nov 2016
Location: Bluffton S.C.
Posts: 2,804
Real Name: Skip
AuSeeker is a name known to all AuSeeker is a name known to all AuSeeker is a name known to all AuSeeker is a name known to all AuSeeker is a name known to all AuSeeker is a name known to all
Quote:
Originally Posted by That_Titanium_4RNR View Post
Next step is turn the car on and then open the hood. Have someone get close to the master cylinder while you press the brakes. They should hear an electric buzzing type sound when you depress the brakes. It should happen every time the brakes are depressed I believe.
If everything is working correctly, the electric motor will come on when you first start the engine and then about every 3 depressions of the brake pedal and stay on for 5 to 15 seconds, if it comes on every time you press the brake pedal or the motor runs too long the accumulator is not holding pressure and should be replaced, the motor should be relatively quiet but you should be able to slightly hear it from the driver's seat, if it's really loud and noticeable the motor maybe worn and either needs to be rebuilt or replaced or it could stop working all together.
__________________
2004 Limited V8

Last edited by AuSeeker; 10-16-2019 at 09:23 PM.
AuSeeker is online now   Reply With QuoteReply With Quote
Old 10-20-2019, 06:22 PM #7
A70BoosTFienD A70BoosTFienD is offline
Junior Member
 
Join Date: Sep 2015
Location: Florida
Posts: 8
A70BoosTFienD is on a distinguished road
A70BoosTFienD A70BoosTFienD is offline
Junior Member
 
Join Date: Sep 2015
Location: Florida
Posts: 8
A70BoosTFienD is on a distinguished road
Quote:
Originally Posted by Good351 View Post
Hello everyone!
I've recently had the brake pedal on my 03 Runner sometimes go mushy.. Like it takes a lot of travel to start engaging the brakes. It's probably 50/50 now working correctly or requiring extra travel. Also, if it does require extra travel, I can then "pump up" the pedal and force it to act normal.

I've read a few posts on checking the brake booster pump.. How does one check this or listen if it is working?

Rear brakes are 2 years old, fronts just over a year (all new parts).
Im having the same issues as you OP. Mine however when it does have a low pedal i hear this fluid squish sound which concerns me... I bled them but no bubbles were found which concerns me further.

Quote:
Originally Posted by AuSeeker View Post
If everything is working correctly, the electric motor will come on when you first start the engine and then about every 3 depressions of the brake pedal and stay on for 5 to 15 seconds, if it comes on every time you press the brake pedal or the motor runs too long the accumulator is not holding pressure and should be replaced, the motor should be relatively quiet but you should be able to slightly hear it from the driver's seat, if it's really loud and noticeable the motor maybe worn and either needs to be rebuilt or replaced or it could stop working all together.
Is rebuilding the unit easy enough to do on a bench with standard tools or does it require some extra steps?
__________________
2008 Limited
1GR VVT-i 4WD
A70BoosTFienD is offline   Reply With QuoteReply With Quote
Old 10-20-2019, 06:53 PM #8
AuSeeker AuSeeker is online now
Senior Member
 
Join Date: Nov 2016
Location: Bluffton S.C.
Posts: 2,804
Real Name: Skip
AuSeeker is a name known to all AuSeeker is a name known to all AuSeeker is a name known to all AuSeeker is a name known to all AuSeeker is a name known to all AuSeeker is a name known to all
AuSeeker AuSeeker is online now
Senior Member
 
Join Date: Nov 2016
Location: Bluffton S.C.
Posts: 2,804
Real Name: Skip
AuSeeker is a name known to all AuSeeker is a name known to all AuSeeker is a name known to all AuSeeker is a name known to all AuSeeker is a name known to all AuSeeker is a name known to all
Quote:
Originally Posted by A70BoosTFienD View Post
Im having the same issues as you OP. Mine however when it does have a low pedal i hear this fluid squish sound which concerns me... I bled them but no bubbles were found which concerns me further.



Is rebuilding the unit easy enough to do on a bench with standard tools or does it require some extra steps?
The complete master cylinder assembly is quite complicated and very expensive because of the ABS system, the electric motor/pump/accumulator brake booster portion, etc. and of course the actual master cylinder portion.

The actual master cylinder portion is not too different from old school master cylinders and can be rebuilt...BUT the portions mentioned above aren't that easy to rebuild if at all...and if the actual master cylinder portion isn't showing signs of leaking where the push rod from the brake pedal enters into it, it shouldn't need to be rebuilt.

That all being said Toyota does sell a kit for the actual master cylinder portion and there is a section in the Toyota shop manual on doing the rebuild.

I can't give you a part number for the kit or a link to the shop manual section for doing the rebuild but both have been posted at least once if not more on this forum.
__________________
2004 Limited V8

Last edited by AuSeeker; 10-20-2019 at 06:55 PM.
AuSeeker is online now   Reply With QuoteReply With Quote
Old 10-21-2019, 12:40 PM #9
Good351's Avatar
Good351 Good351 is offline
Member
 
Join Date: Aug 2009
Location: St. Paul, MN
Posts: 53
Good351 is on a distinguished road
Good351 Good351 is offline
Member
Good351's Avatar
 
Join Date: Aug 2009
Location: St. Paul, MN
Posts: 53
Good351 is on a distinguished road
Quote:
Originally Posted by 95supra View Post
could be a stuck caliper or possibly a front wheel bearing. check both front wheel bearings for excessive play. this with cause the brake pedal to have too much travel at times.
Well, I checked my wheel bearings and the right front is toast.

I also listened for the electric motor on the master cylinder. Every 3 pedal pushes I could hear the motor turn on for a few seconds, then shut off. So I'm thinking it is ok..

I'll have the wheel bearing replaced and see how the brakes respond.
__________________
Current: 03 V8 4Runner. FJ front springs, Bilstein shocks. 236k miles.

Sold: 08 Double Cab TRD Off Road Tacoma. Not stock.

Bought back by Toyota: 99 Tacoma TRD Off Road. Stock. Crushed.
Good351 is offline   Reply With QuoteReply With Quote
Old 10-21-2019, 09:29 PM #10
95supra 95supra is offline
Member
 
Join Date: May 2014
Location: ct
Posts: 80
95supra is on a distinguished road
95supra 95supra is offline
Member
 
Join Date: May 2014
Location: ct
Posts: 80
95supra is on a distinguished road
Quote:
Originally Posted by Good351 View Post
Well, I checked my wheel bearings and the right front is toast.

I also listened for the electric motor on the master cylinder. Every 3 pedal pushes I could hear the motor turn on for a few seconds, then shut off. So I'm thinking it is ok..

I'll have the wheel bearing replaced and see how the brakes respond.
Im pretty sure the bad wheel bearing is the issue. I had the same problem/symptoms you have and the wheel bearing fixed all the issues with my brake pedal travel and also the pump motor coming on too much.
95supra is offline   Reply With QuoteReply With Quote
Old 10-31-2019, 02:04 PM #11
Good351's Avatar
Good351 Good351 is offline
Member
 
Join Date: Aug 2009
Location: St. Paul, MN
Posts: 53
Good351 is on a distinguished road
Good351 Good351 is offline
Member
Good351's Avatar
 
Join Date: Aug 2009
Location: St. Paul, MN
Posts: 53
Good351 is on a distinguished road
Well i finally got the wheel bearing replaced, and I'm happy to report that the brakes are back to normal!

Thanks everyone for your suggestions!
__________________
Current: 03 V8 4Runner. FJ front springs, Bilstein shocks. 236k miles.

Sold: 08 Double Cab TRD Off Road Tacoma. Not stock.

Bought back by Toyota: 99 Tacoma TRD Off Road. Stock. Crushed.
Good351 is offline   Reply With QuoteReply With Quote
Old 10-31-2019, 03:46 PM #12
earthrealm earthrealm is offline
Senior Member
 
Join Date: Jan 2012
Location: darkside of the moon
Posts: 1,379
earthrealm will become famous soon enough
earthrealm earthrealm is offline
Senior Member
 
Join Date: Jan 2012
Location: darkside of the moon
Posts: 1,379
earthrealm will become famous soon enough
Quote:
Originally Posted by Good351 View Post
Well i finally got the wheel bearing replaced, and I'm happy to report that the brakes are back to normal!

Thanks everyone for your suggestions!
wow, wouldnt have believed a faulty wheel bearing could throw off the brakes like that.making the pedal mushy

could someone care to explain the physics behind that??
__________________
2005 v6, galactic grey 4wd auto : pioneer avh 4400bh dvd hu, pyle reverse cam
2003 rav4 titanuim silver 4wd auto......sold
2004 rav4 titanuim silver 4wd auto : pionneer avhx 5500bt hu, pyle reverse cam
earthrealm is offline   Reply With QuoteReply With Quote
Old 10-31-2019, 03:52 PM #13
That_Titanium_4RNR's Avatar
That_Titanium_4RNR That_Titanium_4RNR is offline
Member
 
Join Date: Dec 2018
Location: NC
Age: 22
Posts: 596
Real Name: Michael
That_Titanium_4RNR is a jewel in the rough That_Titanium_4RNR is a jewel in the rough That_Titanium_4RNR is a jewel in the rough
MY GARAGE
That_Titanium_4RNR That_Titanium_4RNR is offline
Member
That_Titanium_4RNR's Avatar
 
Join Date: Dec 2018
Location: NC
Age: 22
Posts: 596
Real Name: Michael
That_Titanium_4RNR is a jewel in the rough That_Titanium_4RNR is a jewel in the rough That_Titanium_4RNR is a jewel in the rough
MY GARAGE
Quote:
Originally Posted by earthrealm View Post
wow, wouldnt have believed a faulty wheel bearing could throw off the brakes like that.making the pedal mushy

could someone care to explain the physics behind that??
my theory is that when a wheel bearing fails sometimes it will start to bow out a bit. Sort of like a car with a lot of negative camber. When this happens the disc is on the same axis as the wheel hub and the pads and caliper are on the axis as the spindle (the correct axis with little to no camber). Because of this difference in axises (sp?) the brake pads are only slightly engaging and causing slippage and soft pedal issues. My buddy has a ram with wide wheels and spacers and had the same type of thing going on with his until we fixed the wheel hub. Once we did that, the 2 axis were brought back into alignment and the brake calipers and pads were meshed perfectly again allowing for a nice full contact patch
__________________
Titanium Metallic 2006 Limited 4WD V8 | 5th Gen Brake Swap | Slyfox AIP Bypass | TPMS Bypass | Fog Light Mod | Everything else is in the Build Thread
That_Titanium_4RNR is offline   Reply With QuoteReply With Quote
Old 11-01-2019, 09:30 PM #14
95supra 95supra is offline
Member
 
Join Date: May 2014
Location: ct
Posts: 80
95supra is on a distinguished road
95supra 95supra is offline
Member
 
Join Date: May 2014
Location: ct
Posts: 80
95supra is on a distinguished road
Quote:
Originally Posted by That_Titanium_4RNR View Post
my theory is that when a wheel bearing fails sometimes it will start to bow out a bit. Sort of like a car with a lot of negative camber. When this happens the disc is on the same axis as the wheel hub and the pads and caliper are on the axis as the spindle (the correct axis with little to no camber). Because of this difference in axises (sp?) the brake pads are only slightly engaging and causing slippage and soft pedal issues. My buddy has a ram with wide wheels and spacers and had the same type of thing going on with his until we fixed the wheel hub. Once we did that, the 2 axis were brought back into alignment and the brake calipers and pads were meshed perfectly again allowing for a nice full contact patch
wow very good description of whats going on when the wheel bearing has excessive play. the only thing I will add is, the reason the brake pedal gets mushy or has more travel is because the rotor being on the wrong cambered angle causes the brake pads to push the caliper pistons back in the caliper way more than they should be pushed in.
95supra is offline   Reply With QuoteReply With Quote
Reply

Tags
brake , pedal , pump , travel , working

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

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 On

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Wiring diagram for gas pedal position sensor and brake pedal sensor? Seymore Butts 4th Gen T4Rs 0 05-23-2018 03:38 PM
Did tundra brake upgrade and brake pedal mushy. 3rdgenfan 3rd gen T4Rs 5 10-25-2015 08:51 PM
4th Gen Mushy Brake Pedal Halfsmoke89 4th Gen T4Rs 14 10-13-2014 08:02 PM
Hesitation and mushy gas pedal help Golfinz 3rd gen T4Rs 12 05-29-2014 09:40 PM
Spongy/Long travel Brake Pedal w/ Tundra brake upgrade 2002_thundercloud 3rd gen T4Rs 8 06-22-2012 01:52 AM

Powered by vBadvanced CMPS v3.2.2

All times are GMT -4. The time now is 08:00 PM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Feedback Buttons provided by Advanced Post Thanks / Like (Lite) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging (Lite) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
***This site is an unofficial Toyota site, and is not officially endorsed, supported, authorized by or affiliated with Toyota. All company, product, or service names references in this web site are used for identification purposes only and may be trademarks of their respective owners. The Toyota name, marks, designs and logos, as well as Toyota model names, are registered trademarks of Toyota Motor Corporation***Ad Management plugin by RedTyger
 
Copyright © 2019


Garage Plus vBulletin Plugins by Drive Thru Online, Inc.