XJ/TJ/ZJ Front Knuckle Repair - Brake Pad Grooves - Page 3 - 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 Wrangler Forums > TJ Wrangler Technical Forum > XJ/TJ/ZJ Front Knuckle Repair - Brake Pad Grooves

Jeep Grand Cherokee Mirror - Side ViewJeep Grand Cherokee Header PanelTJ 5.25" Speaker Adapters - NalinMFG

Reply
Unread 04-14-2012, 09:09 AM   #31
ratmonkey
R.I.P.
 
ratmonkey's Avatar
1997 ZJ 
 
Join Date: Dec 2006
Location: , Pennsylvania
Posts: 19,805
Yes, it could cause enough drag to have a pull.

I've done this on a few sets of knuckles.
The last set i did had grooves worn almost entirely across the slide.
I use arc with hard facing electrodes. Now the slides are harder than the pads.

__________________
'97 zj 5.2, some stuff, some other suff, and some things that even work sometimes.

ratmonkey is offline   Reply With Quote
Unread 04-14-2012, 09:22 AM   #32
predawn
Registered User
1997 TJ Wrangler 
 
Join Date: Jan 2011
Location: philly, PA
Posts: 273
would you notice it again immediately after fresh pads?
predawn is offline   Reply With Quote
Unread 04-14-2012, 10:38 AM   #33
ratmonkey
R.I.P.
 
ratmonkey's Avatar
1997 ZJ 
 
Join Date: Dec 2006
Location: , Pennsylvania
Posts: 19,805
Quote:
Originally Posted by predawn View Post
would you notice it again immediately after fresh pads?
fresh pads will stick in the divots just the same as worn ones.
__________________
'97 zj 5.2, some stuff, some other suff, and some things that even work sometimes.

ratmonkey is offline   Reply With Quote
Unread 10-10-2012, 09:58 AM   #34
DanZ51
Registered User
2004 TJ Wrangler 
 
Join Date: Feb 2009
Location: Wallingford, VT, Vermont
Posts: 836
Ratmonkey, how hard was it to smooth out the hardface weld? Did you use a file, grinder, other? I've hardfaced engineer equipment before, but nothing that had to be shaped after. I know there is a hardfaced TIG rod available but have never used it, this might the best application.
__________________
"I will always be an American Soldier"
DanZ51 is offline   Reply With Quote
Unread 10-10-2012, 04:03 PM   #35
mrblaine
Wizard of Brakes
 
mrblaine's Avatar
1999 TJ Wrangler 
 
Join Date: Dec 2004
Location: Quail Valley, California
Posts: 25,586
Quote:
Originally Posted by DanZ51 View Post
Ratmonkey, how hard was it to smooth out the hardface weld? Did you use a file, grinder, other? I've hardfaced engineer equipment before, but nothing that had to be shaped after. I know there is a hardfaced TIG rod available but have never used it, this might the best application.
You are welcome to use the special rod, but a normal mig weld will pull the carbon out of the knuckle as it freezes and it accomplishes the exact same thing. The new surface when finished with hard grinding disc is now much harder than the surrounding iron knuckle that it will never wear down again.

Try it on a junk knuckle and you'll be pretty impressed at how hard it the weld winds up being.
__________________
I am Savvy
blackmagicbrakes.com
mrblaine is offline   Reply With Quote
Unread 10-11-2012, 06:57 AM   #36
ratmonkey
R.I.P.
 
ratmonkey's Avatar
1997 ZJ 
 
Join Date: Dec 2006
Location: , Pennsylvania
Posts: 19,805
I wouldn't go out of my way to buy hard face Rod, but I had it, so I used it.

I used a hard grinding wheel to rough it back into shape and roloc sanding discs to finish it up.
__________________
'97 zj 5.2, some stuff, some other suff, and some things that even work sometimes.

ratmonkey is offline   Reply With Quote
Unread 10-13-2012, 02:16 PM   #37
illinicj
Registered User
1979 CJ7 
 
Join Date: Nov 2007
Location: Lake Zurich, IL
Posts: 390
Thanks for the write up. Just did my brakes today and was surprised to see these divots - didn't know it was a common problem and wasn't sure how to fix. I wasn't sure it was a good idea to weld on the cast knuckle, so I just decided to figure it out later and put the brakes together without fixing them. I couldn't believe NAPA was asking $750 for a pair of knuckles... Yikes. Now that I see you guys have welded them up, I'll have to go try that later. Much better solution for me!
illinicj is offline   Reply With Quote
Unread 10-13-2012, 08:25 PM   #38
mrblaine
Wizard of Brakes
 
mrblaine's Avatar
1999 TJ Wrangler 
 
Join Date: Dec 2004
Location: Quail Valley, California
Posts: 25,586
Quote:
Originally Posted by illinicj View Post
Thanks for the write up. Just did my brakes today and was surprised to see these divots - didn't know it was a common problem and wasn't sure how to fix. I wasn't sure it was a good idea to weld on the cast knuckle, so I just decided to figure it out later and put the brakes together without fixing them. I couldn't believe NAPA was asking $750 for a pair of knuckles... Yikes. Now that I see you guys have welded them up, I'll have to go try that later. Much better solution for me!
That 750 they want makes the Vanco kit with all new brake parts look like a smokin' deal and the best part is the divots are permanently fixed.
__________________
I am Savvy
blackmagicbrakes.com
mrblaine is offline   Reply With Quote
Unread 01-10-2013, 06:29 PM   #39
oakmckinley
Registered User
1999 TJ Wrangler 
 
Join Date: Mar 2010
Location: Minneapolis, MN
Posts: 1,446
Hey just a inexperienced question.
When I installed new brakes on my TJ/XJ I just filed the spot flat.

My question is how does it move the caliper closer to the hub? when the caliper is still held in place by the bolts?
__________________
1999 TJ
2000 XJ Cherokee
2010 Mustang
1964 Ford Fairlane 500
oakmckinley is offline   Reply With Quote
Unread 01-10-2013, 08:02 PM   #40
oakmckinley
Registered User
1999 TJ Wrangler 
 
Join Date: Mar 2010
Location: Minneapolis, MN
Posts: 1,446
Okay, just did a little more searching on this. Essentially because we have floating calipers, the piston pushes the inside pad to the rotor and when it meets, it forces the caliper to move thus pushing the outside pad towards the rotor. Is that correct? So the bolts act like guide pins?

So I still have the same question as above, those "rails" with the divets, how do they have any effect on uneven pad where?
__________________
1999 TJ
2000 XJ Cherokee
2010 Mustang
1964 Ford Fairlane 500
oakmckinley is offline   Reply With Quote
Unread 01-11-2013, 12:36 AM   #41
cologc46
Senior Member
 
cologc46's Avatar
2006 TJ Wrangler 
 
Join Date: Sep 2007
Location: Loveland, CO
Posts: 521
Quote:
Originally Posted by oakmckinley View Post
Okay, just did a little more searching on this. Essentially because we have floating calipers, the piston pushes the inside pad to the rotor and when it meets, it forces the caliper to move thus pushing the outside pad towards the rotor. Is that correct? So the bolts act like guide pins?

So I still have the same question as above, those "rails" with the divets, how do they have any effect on uneven pad where?
My understanding is: The backside brake pad hangs up in the divot, and so that pad does not evenly contact the rotor. The outside pad may contact evenly, but the backside pad will wear at an angle. I would expect this degrades the braking performance enough that I would fix it (I want to upgrade to the vanco kit anyway).

That said, my previous jeep was a 94ZJ. At 100K miles, my knuckles were still in pretty good shape. The pads were wearing ok. I figured to be replacing the knuckles on the next brake job, but instead, I sold it when and bought this TJ.
__________________
||||
cologc46 is offline   Reply With Quote
Unread 01-11-2013, 01:21 AM   #42
oakmckinley
Registered User
1999 TJ Wrangler 
 
Join Date: Mar 2010
Location: Minneapolis, MN
Posts: 1,446
I follow what your saying.
When I did both my Jeeps I just filed the divot. I didn't "build" up the surface by welding.
So thats what I am asking, why the need to build up the area and then file it back even.
__________________
1999 TJ
2000 XJ Cherokee
2010 Mustang
1964 Ford Fairlane 500
oakmckinley is offline   Reply With Quote
Unread 01-11-2013, 06:02 AM   #43
mrblaine
Wizard of Brakes
 
mrblaine's Avatar
1999 TJ Wrangler 
 
Join Date: Dec 2004
Location: Quail Valley, California
Posts: 25,586
Quote:
Originally Posted by oakmckinley View Post
Okay, just did a little more searching on this. Essentially because we have floating calipers, the piston pushes the inside pad to the rotor and when it meets, it forces the caliper to move thus pushing the outside pad towards the rotor. Is that correct? So the bolts act like guide pins?
You have the movements correct but the bolts don't act as guide pins. The bolt actually bolt the guide sleeves to the knuckle. There is a rubber sleeve with dust bellows on each in and the guide sleeve is inside that.

Quote:
So I still have the same question as above, those "rails" with the divets, how do they have any effect on uneven pad where?
There is a relatively precise relationship between the cast sliders and the pad groove and hook.

If the divots get too deep or to much material filed away, the pad can move away from it's intended location. The other thing is both pads need to be resting on the top slider roughly in the same spot when the caliper applies pressure. If one has to move further to hit the slider, you are potentially giving up some pedal travel because the caliper can move radially to the knuckle or tip slightly.

Also bad things happen if you build up the cast ears and the pads can't slide properly.
__________________
I am Savvy
blackmagicbrakes.com
mrblaine is offline   Reply With Quote
Unread 04-12-2013, 02:56 PM   #44
cooky
Newbie
 
cooky's Avatar
1997 ZJ 
 
Join Date: Mar 2013
Location: WINNIPEG, Manitoba
Posts: 8
Very helpful. Worked like a charm!
Thank you!
cooky is offline   Reply With Quote
Unread 12-02-2013, 06:27 AM   #45
V65Ozzie
Registered User
1998 ZJ 
 
Join Date: Feb 2012
Location: Wilson, nc
Posts: 528
Quote:
Originally Posted by sprintagogo View Post
Done this half-a-dozen times now as I have been through a fair few front axles (but thats a different story!). It works great and is far, far, far cheaper and easier than replacing knuckles. To be honest, even if you don't get a perfect finish it is still going to be better than the hole you are starting off with. If you do grind too much off you can always hit it with a welder a second time but ideally it should be done in one pass as you have done.
Done this myself on more than on jeep/chrysler product
__________________
My ZJ has traction control, I call it my right foot.....
V65Ozzie is offline   Reply With Quote
Reply
Thread Tools


Suggested Threads





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.