Go Back   DIY Chatroom Home Improvement Forum > Do It Yourself > Automotive Repairs

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 06-20-2014, 08:35 PM   #1
Member
 
Join Date: Dec 2009
Location: Columbus, OH
Posts: 326
Rewards Points: 250
Default

Brake pedal still spongy after multiple bleeds


Hi everyone. I have a '97 Nissan XE hardbody pickup that is having brake trouble. The brake pedal is still very spongy after we've bled it at least 5 times in the last 3 days. We just finished bleeding it about 20 minutes ago and we did 2-3 cycles at each wheel. This time around the fluid was perfectly clean and solid with no air bubbles.

We've also checked both check valves from the booster. We removed the hose from the brake booster and verified a vacuum and we disconnected the valve in between the booster and intake and verified that it's working properly as well.

We also put a brand new master cylinder on today and it's still doing the same thing. We've tried absolutely everything we can think of. The only other scenario we can think of is that both front calipers and both rear cylinders are frozen, but wouldn't the brake pedal still be firm if this was the case?

We are at a loss and have no idea where to go next. If any of you have any ideas, we'd greatly appreciate it. Thanks so much.

Jesse

jpearson311 is offline   Reply With Quote
Old 06-20-2014, 08:50 PM   #2
Member
 
Join Date: Jan 2010
Location: Saskatoon Sk. Canada
Posts: 420
Rewards Points: 252
Default

Brake pedal still spongy after multiple bleeds


Did you bench bleed your new master cylinder? Perhaps you finally got your system bled and then changed the master?

daveb1 is offline   Reply With Quote
The Following User Says Thank You to daveb1 For This Useful Post:
jpearson311 (06-20-2014)
Old 06-20-2014, 09:03 PM   #3
Member
 
Join Date: Dec 2009
Location: Columbus, OH
Posts: 326
Rewards Points: 250
Default

Brake pedal still spongy after multiple bleeds


Quote:
Originally Posted by daveb1 View Post
Did you bench bleed your new master cylinder? Perhaps you finally got your system bled and then changed the master?
No we didn't bench bleed it, but the entire system has been bled twice since we've installed the new MC.

Jesse
jpearson311 is offline   Reply With Quote
Old 06-20-2014, 09:07 PM   #4
Member
 
Join Date: Feb 2008
Posts: 53
Rewards Points: 77
Default

Brake pedal still spongy after multiple bleeds


Did you check to see if there is a bleeding sequence from one wheel to the other?
christoff is offline   Reply With Quote
The Following User Says Thank You to christoff For This Useful Post:
jpearson311 (06-20-2014)
Old 06-20-2014, 09:13 PM   #5
Member
 
Join Date: Feb 2008
Posts: 53
Rewards Points: 77
Default

Brake pedal still spongy after multiple bleeds


If you have Abs,it might also be a consideration when bleeding.
christoff is offline   Reply With Quote
Old 06-20-2014, 09:13 PM   #6
Member
 
Join Date: Dec 2009
Location: Columbus, OH
Posts: 326
Rewards Points: 250
Default

Brake pedal still spongy after multiple bleeds


Quote:
Originally Posted by christoff View Post
Did you check to see if there is a bleeding sequence from one wheel to the other?
No. We bled them the "traditional" way. Rear passenger, rear driver, front passenger, front driver.

Jesse
jpearson311 is offline   Reply With Quote
Old 06-20-2014, 09:20 PM   #7
Member
 
Join Date: Feb 2008
Posts: 53
Rewards Points: 77
Default

Brake pedal still spongy after multiple bleeds


Maybe it would be an idea to go to a nissan site to see if there is a special way to bleed. chris
christoff is offline   Reply With Quote
The Following User Says Thank You to christoff For This Useful Post:
jpearson311 (06-20-2014)
Old 06-20-2014, 09:56 PM   #8
Member
 
Join Date: Mar 2011
Location: NW Wisconsin
Posts: 453
Rewards Points: 254
Default

Brake pedal still spongy after multiple bleeds


If it has ABS, most scan tools provide a brake bleed function that cycles all the valves to move any air out of the valve body. I've had a few over the years that were just awful to bleed out.

Also, you could try the bleed procedure for a diagonally split system (LR RF RR LF). Have seen them split this way on many imports and domestics over the years.
Marqed97 is offline   Reply With Quote
Old 06-20-2014, 11:55 PM   #9
Member
 
Join Date: Sep 2011
Location: minnesota
Posts: 285
Rewards Points: 254
Default

Brake pedal still spongy after multiple bleeds


Are you sure the rear brakes are adjusted properly? If they are to far out they will make the brakes feel spongy
cjm94 is online now   Reply With Quote
The Following User Says Thank You to cjm94 For This Useful Post:
rustyjames (06-21-2014)
Old 06-21-2014, 03:10 PM   #10
Pro Flooring Installer
 
rusty baker's Avatar
 
Join Date: Feb 2009
Location: SW Missouri
Posts: 3,985
Rewards Points: 2,240
Default

Brake pedal still spongy after multiple bleeds


Quote:
Originally Posted by jpearson311 View Post
No we didn't bench bleed it, but the entire system has been bled twice since we've installed the new MC.

Jesse
Master cylinders really need to be bench bled. That is most likely your problem.
__________________
The ads in my post are there without my permission. I do not endorse any of the products.
Semi-Retired Installer
Installing since 1973
rusty baker is offline   Reply With Quote
Old 06-21-2014, 08:12 PM   #11
Member
 
Join Date: Dec 2009
Location: Columbus, OH
Posts: 326
Rewards Points: 250
Default

Brake pedal still spongy after multiple bleeds


Well, there is an update and it's not good. So I did a power booster test last night and it totally failed. Spent over $200 today and installed a new booster. The pedal was definitely harder, but still ultimately soft. I decided to remove the front wheels to inspect the brakes and what do you know? The pads on both sides were seized to the rotors, the rotors were rusty as hell, the passenger side caliper was seized, and the driver side caliper piston came clean out of the caliper when the brake pedal was pressed and spilled brake fluid all over the floor.

Now I have to return the brake booster and spend $160 for new calipers, pads, and rotors. Awesome, what an exciting day I had. What's the moral of the story? Don't ever listen to your lazy hippie neighbor when he tells you all it needs is the brakes to be bled. Thanks for your help you guys.

Jesse
jpearson311 is offline   Reply With Quote
The Following User Says Thank You to jpearson311 For This Useful Post:
oh'mike (06-22-2014)
Old 06-26-2014, 06:18 AM   #12
First Home N00b
 
Join Date: Jun 2014
Location: Bordentown, NJ
Posts: 183
Rewards Points: 154
Default

Brake pedal still spongy after multiple bleeds


Quote:
Originally Posted by jpearson311 View Post
Well, there is an update and it's not good. So I did a power booster test last night and it totally failed. Spent over $200 today and installed a new booster. The pedal was definitely harder, but still ultimately soft. I decided to remove the front wheels to inspect the brakes and what do you know? The pads on both sides were seized to the rotors, the rotors were rusty as hell, the passenger side caliper was seized, and the driver side caliper piston came clean out of the caliper when the brake pedal was pressed and spilled brake fluid all over the floor.

Now I have to return the brake booster and spend $160 for new calipers, pads, and rotors. Awesome, what an exciting day I had. What's the moral of the story? Don't ever listen to your lazy hippie neighbor when he tells you all it needs is the brakes to be bled. Thanks for your help you guys.

Jesse
Power booster should not impact pedal softness because you bleed with car not running (no boost assist). Power booster simply reduces the pressure the driver needs to apply to the pedal to get braking action (mechanical advantage).

Take off the rear wheels and get the brakes and hardware squared away before continuing.
95PGTTech is offline   Reply With Quote
Old 06-26-2014, 09:44 AM   #13
Member
 
Join Date: Dec 2009
Location: Columbus, OH
Posts: 326
Rewards Points: 250
Default

Brake pedal still spongy after multiple bleeds


Quote:
Originally Posted by 95PGTTech View Post
Power booster should not impact pedal softness because you bleed with car not running (no boost assist). Power booster simply reduces the pressure the driver needs to apply to the pedal to get braking action (mechanical advantage).

Take off the rear wheels and get the brakes and hardware squared away before continuing.
If you run the engine for a minute or so, turn it off, and then pump the brake pedal, if the pedal doesn't incrementally get firmer, then a lot of the time, the booster is bad. It's bad because it's not holding it's vacuum pressure. Regardless, one of the rear wheel cylinders was leaking so we replaced both of them and the front break hoses. It stops now, but the pedal still goes really low. Thanks though. At this point, it's a mystery.

Jesse
jpearson311 is offline   Reply With Quote
Old 06-26-2014, 10:59 AM   #14
Member
 
47_47's Avatar
 
Join Date: Sep 2007
Location: Springville, NY
Posts: 1,501
Rewards Points: 590
Default

Brake pedal still spongy after multiple bleeds


You need a direction to go.

Place trans in park or chock the wheels, e-brake off. Start engine. Rapidly press the brake pedal (release, press, release, press...). If you can pump it up, you have air and brakes need bleeding. If you can't basic brake problems.

For a power booster test, key off, depress brake pedal. You should get 2-3 hits of power assist. If you don't, either leaking booster or bad check valve. On the last hit keep your foot on the brake pedal. Start engine, pedal should fall slightly.
__________________
What we've got here is... failure to communicate. Some men you just can't reach. So you get what we had here last week, which is the way he wants it... well, he gets it.
47_47 is offline   Reply With Quote
Old 06-26-2014, 11:27 AM   #15
First Home N00b
 
Join Date: Jun 2014
Location: Bordentown, NJ
Posts: 183
Rewards Points: 154
Default

Brake pedal still spongy after multiple bleeds


Quote:
Originally Posted by jpearson311 View Post
If you run the engine for a minute or so, turn it off, and then pump the brake pedal, if the pedal doesn't incrementally get firmer, then a lot of the time, the booster is bad. It's bad because it's not holding it's vacuum pressure. Regardless, one of the rear wheel cylinders was leaking so we replaced both of them and the front break hoses. It stops now, but the pedal still goes really low. Thanks though. At this point, it's a mystery.

Jesse
You're over-complicating it again. Base brake system, brake hydraulics, and vacuum or power assist are all completely separate systems and should be diagnosed and serviced separately.

Visual inspection of all base brake components - hardware, bolts, rotors, pads, soft and hard lines, shoes, drums, wheel cylinders, etc. Replace as necessary due to visual failure.

Hydraulics - now depress brake pedal with truck completely off - do all four wheels engage correctly? If not, address air in lines, master cylinder, proportioning valve, ABS pump, etc.

Vaccuum assist - now that all those are done, turn truck on and address this. Pedal should be high and hard if the top 2 system are addressed when completely off. When you run it, pedal should be softer as the booster is giving you assist. The booster is such a large vacuum demand most times it is diagnosed by customer first noticing engine running concerns.

95PGTTech is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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 Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
brake pedal travel & force Yoyizit Automotive Repairs 3 09-07-2010 09:00 PM
No Brake Pedal 2004 GMC Safari Van tvlfleming Automotive Repairs 2 11-27-2009 06:02 PM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.