front brake issue - Ford Powerstroke Diesel Forum

 
LinkBack Thread Tools Display Modes
post #1 of 8 Old 09-01-2011, 04:29 AM Thread Starter
JFK
Powerstroke.org Rookie
 
Join Date: Dec 2006
Posts: 10
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Feedback Score: 0 reviews
Exclamation front brake issue

I installed new front calipers, rotors and pads. When applying the brakes grab with appropriate force for 3/4 of the rotation of the wheel and the other 1/4 rotation grabs really hard, likelihood the rotors are warped. You can feel this in the brake pedal. I have checked the rotors for true with a dial indicator and they are true. I also checked the calipers and both pistons seem to be engaging at the same time. Does anyone have any ideas as to why this is happening?
JFK is offline  
post #2 of 8 Old 09-01-2011, 05:36 AM
Premium Member
 
Term3's Avatar
 
Join Date: Feb 2011
Location: Edmonton, Alberta Canada
Posts: 3,957
Thanks: 0
Thanked 34 Times in 32 Posts
Mentioned: 0 Post(s)
Quoted: 1 Post(s)
Feedback Score: 1 reviews
Did you do a brake pad break-in?

SCT, no studs...yet, Dual OEM intake air filter housings, Banks intercooler & intake elbow, Banks exhaust system, Windrunner ported intake manifold, Bullet Proof Diesel remote oil cooler & thermostat, AirDog2 (plus a couple spares), Power steering filter (Amsoil dual-bypass), MagTec deep ATF pan, Electric oil pre-lub pump, Dakota Digital gauges.
Term3 is offline  
post #3 of 8 Old 09-01-2011, 05:57 AM
Compression Ignition Addict
 
Join Date: Dec 2007
Posts: 6,204
Thanks: 7
Thanked 233 Times in 224 Posts
Mentioned: 6 Post(s)
Quoted: 75 Post(s)
Feedback Score: 3 reviews
"Warping" rotors is a myth (as you've discovered with a dial indicator) and while it may have applied to "single-plane" rotors it has nothing to do with the finned, dual-planed, rotors your truck has...

It's caused by the surface of the rotor being different is some spots than others (cutting the rotor resurfaces it, fixes it, so people think it got re-trued because it was warped) BUT it's the new, even, braking surface that it needed.

So, you can try to give it a new surface yourself with a DA and some 80grit or, if you have to, it can be resurfaced on a brake lathe (NOT if it's drilled though)

Term3 has a good point, did you bed the new pads when installing them? If not, you can deposit pad material on the rotors and actually cause the pulse.
NoRalPh is offline  
post #4 of 8 Old 09-01-2011, 09:26 AM Thread Starter
JFK
Powerstroke.org Rookie
 
Join Date: Dec 2006
Posts: 10
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Feedback Score: 0 reviews
yes i did a break in. this 'pulsing' was happening during break in. during the break in the pulsing was bearly there for the first and second time i applied the brakes. after that the pulsing was bad but seamed to get better after subsequent braking but is still there. should i have the rotors turned again?
JFK is offline  
post #5 of 8 Old 09-01-2011, 10:52 AM
Compression Ignition Addict
 
Join Date: Dec 2007
Posts: 6,204
Thanks: 7
Thanked 233 Times in 224 Posts
Mentioned: 6 Post(s)
Quoted: 75 Post(s)
Feedback Score: 3 reviews
Take 'em out and Heat 'em up (you should actually be able to "smell" brakes if you did it right) but not Too hot

6-7 moderate stops in a row from 50 to 5 without stopping. Might be all it needs.

How did you do the break-in?
NoRalPh is offline  
post #6 of 8 Old 09-01-2011, 06:50 PM Thread Starter
JFK
Powerstroke.org Rookie
 
Join Date: Dec 2006
Posts: 10
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Feedback Score: 0 reviews
I actually did 8 to 10 hard brakes from 50 - 60 down to about 5 or 10 mph. i tried to do them one right after the other but conditions not accomodating. the longest between brakes was about 3 or 4 minutes. The pulsing started immediataly then after break in seemed to be minimal perhaps dissapearing but after normal driving the pulsing seems to worsen.
JFK is offline  
post #7 of 8 Old 09-01-2011, 06:52 PM Thread Starter
JFK
Powerstroke.org Rookie
 
Join Date: Dec 2006
Posts: 10
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Feedback Score: 0 reviews
can i just do another break in or do i need to turn the rotors and clean the brake pads and try again. i have never had such problems. usually just hard breaking 4 or 5 times and good to go. wth!
JFK is offline  
post #8 of 8 Old 09-02-2011, 06:07 AM
Compression Ignition Addict
 
Join Date: Dec 2007
Posts: 6,204
Thanks: 7
Thanked 233 Times in 224 Posts
Mentioned: 6 Post(s)
Quoted: 75 Post(s)
Feedback Score: 3 reviews
They should re-bed, give it a try!
NoRalPh is offline  
Reply

Tags
brakes

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Ford Powerstroke Diesel Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may 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 On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome