Spongy Brake peddle - Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > TJ Jeep Wrangler Forum > TJ Tech Forum

Join Wrangler Forum Today


Reply
 
Thread Tools

Please support our sponsors and let them know you heard about them on WranglerForum.com
Old 05-20-2013, 06:26 PM   #1
Jeeper
 
wml52's Avatar
 
Join Date: May 2012
Location: Upstate NY
Posts: 21
Spongy Brake peddle

Last week I replaced all the hard lines in my 2000 TJ with stainless steel lines because the OEM lines rusted through. While I was at it I also replaced the master cylinder, rebuilt the calipers (4) and replaced the proportioning valve because I did away with the ABS pump assy.

I bench bled the MC until I saw no air bubbles prior to installing it. Hooked everything up, gravity bled the lines until fluid starting coming out and then bled the system using a Mityvac pump. After bleeding the system I still had a spongy peddle, so thinking I still may have some air in the system I decided to bleed the system again using the old tried and true method of 2 person bleed.

Well long story short, I put about 2 quarts of fluid through the system could see no signs of bubbles anywhere from the calipers yet after all that I still have a rather spongy peddle.

Any thoughts as to what might be the issue? I know most of you will say still has air in the lines but like I said after 2 quarts of fluid being pumped through I didnít see any signs of bubbles in the lines.

Any help would be appreciated.

Bill

wml52 is offline   Quote
Old 05-20-2013, 06:49 PM   #2
Jeeper
 
Big Cole's Avatar
 
Join Date: Jan 2012
Location: Thousand Oaks
Posts: 1,897
Did you install the calipers correctly with the bleeder valves pointed up? When I received my new rear axle the calipers were installed upside down because the builder swapped sides on accident. I couldn't successfully bleed the brakes until move each caliper to its original axle shaft.

Big Cole is offline   Quote
Old 05-24-2013, 07:47 PM   #3
Jeeper
 
wml52's Avatar
 
Join Date: May 2012
Location: Upstate NY
Posts: 21
Yes they are in the correct location = On top
wml52 is offline   Quote
Old 05-24-2013, 08:20 PM   #4
Jeeper
 
TreeClimber1's Avatar
 
Join Date: Nov 2011
Location: Washington
Posts: 390
1) Did you replace the caliper hoses also?
2) The replacement 'stainless steel lines', are they 'hardlines' or 'braided flex (hose)'?
3) The deletion of the ABS, did that create a 'high spot' in the lines, whereby air might be trapped?

[and for what it's worth, I personally think you're already on the correct diagnosis with it being air still trapped in the system]
__________________
1992 YJ, 401 V8, EFI, TH400, Atlas, D60s, Detroits, Warn 8274, Cage, 37 Krawlers
1997 TJ, 350 V8, EFI, TH400, Atlas 4spd, D60s, Detroits, Warn 12000, Cage, 40 Kevlars
TTC 1994, TTC 2012, Trail Tour participant.
TreeClimber1 is offline   Quote
Old 05-24-2013, 08:29 PM   #5
Jeeper
 
flflash's Avatar
 
Join Date: Mar 2013
Posts: 519
One more thing to go along with the above, have a look at your proportioning valve. Is the pin sticking out at the end ( wish I had a picture sorry ) sometimes while bleeding a complete system the proportioning valve will shift and not allow you to fully bleed one end.
flflash is offline   Quote
Old 05-24-2013, 09:11 PM   #6
Jeeper

WF Supporting Member
 
Black Magic Brakes's Avatar
 
Join Date: May 2011
Posts: 2,309
Quote:
Originally Posted by flflash View Post
One more thing to go along with the above, have a look at your proportioning valve. Is the pin sticking out at the end ( wish I had a picture sorry ) sometimes while bleeding a complete system the proportioning valve will shift and not allow you to fully bleed one end.

You are correct in every aspect except for the pin part. Ours don't have them. The small hex at the front of the combo valve that has the rubber cap on it actually houses the front to back proportioning valve.

The shuttle valve inserts from the other end and has no way to move a pin for an external indicator that it is shifted.

What does happen is when it is shifted, the brake light on the dash turns on to tell you there is a problem.
__________________
I am Savvy, I am the brake Wizard.
Black Magic Brakes is offline   Quote
Old 05-24-2013, 09:18 PM   #7
Jeeper
 
flflash's Avatar
 
Join Date: Mar 2013
Posts: 519
Thanks for clarifying that BMB I honestly havent looked on that system.

BTW I'm extremely happy with the rotors and pads still determining which route I'm going to go on the rear, keep the 44 and add disc or go 8.8 with disc.
flflash is offline   Quote
Old 05-24-2013, 10:17 PM   #8
Jeeper

WF Supporting Member
 
Black Magic Brakes's Avatar
 
Join Date: May 2011
Posts: 2,309
Quote:
Originally Posted by flflash View Post
Thanks for clarifying that BMB I honestly havent looked on that system.

BTW I'm extremely happy with the rotors and pads still determining which route I'm going to go on the rear, keep the 44 and add disc or go 8.8 with disc.
Well, if you find a cheap 8.8 that someone stole the backing plates off of, we have both, 8.8 and 44 conversions.

__________________
I am Savvy, I am the brake Wizard.
Black Magic Brakes is offline   Quote
Reply

Thread Tools

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




Download our Mobile App

» Featured Product

All times are GMT -5. The time now is 12:34 AM.


User Alert System provided by Advanced User Tagging v3.1.0 (Pro) - vBulletin Mods & Addons Copyright © 2015 DragonByte Technologies Ltd.

Jeepģ, Wrangler, Liberty, Wagoneer, Cherokee, and Grand Cherokee are copyrighted and trademarked to Chrysler Motors LLC.
Wranglerforum.com is not in any way associated with the Chrysler Motors LLC