Stuck brake, what to inspect? - JeepForum.com
 1Likes
Reply
 
LinkBack Thread Tools
post #1 of 17 Old 03-29-2021, 04:43 PM Thread Starter
BaileyNB
Registered User
1947 CJ2A 
 
Join Date: Mar 2018
Location: Savannah
Posts: 79
Stuck brake, what to inspect?

Hey guys. 1992 Jeep Cherokee.

Awhile back my brakes were squeeling, so I did a brake job. The rotors looked like the stock ones from '92 and kind of rough, so I replaced them. Calipers looked fine after cleaning them up. I must not have had the right rotor seated properly because after awhile I hit a bump and, the rotor got a little off and was rubbing against the dust shield. I got it home, but the new pads and rotor were damaged.

I replaced the rotor and pads again and made sure everything was seated properly before putting the wheel back on. I also upgraded to ZJ disc brakes, the 1995/96 master cylinder and booster, and a ZJ proportioning valve. The brakes were working great for a couple of weeks driving around town and short highway trips.

Yesterday, I'm making my third or fourth trip to the hardware store (yay electrical work on the house!) and the front right brake sticks. I didn't have any real option once I got to the store, so I ended up driving it back to the house, about 20 miles. Obviously, the brake was smoking by the time I got home, I just didn't have the option to wait hours for a tow home on a Sunday, plus roadside assistance only covers 15 miles. When I brought it out of the driveway today to move the Jeep into the shop, the brake released and seemed fine.

I suspect I should take the tire off and inspect the caliper, pads, and rotor. I'm pretty sure I'll be replacing those. Should I inspect anything else while I'm in there, like the wheel hub? Should I worry about any problems from that heat?

BaileyNB is offline  
Sponsored Links
Advertisement
 
post #2 of 17 Old 03-29-2021, 05:33 PM
CJ7-Tim
Real Jeeps have dents
 
CJ7-Tim's Avatar
2000 XJ Cherokee 
 
Join Date: Apr 2002
Location: out in the garage - Minneapolis
Posts: 28,925
Inspect the slide surfaces the brake pads move on for divots or other unusual wear that could cause binding. Also replace the soft brake lines to the calipers. Old soft brake lines will degrade and can cause random blockages in the fluid return flow, leading to a stuck caliper. I would wait until the unit hub shows signs of damage before replacing
superj likes this.

“We the people are the rightful masters of both Congress and the Courts,
not to overthrow the Constitution but to overthrow the men who would pervert the Constitution” Abraham Lincoln, 1859.
CJ7-Tim is offline  
post #3 of 17 Old 03-30-2021, 01:42 PM
UKXJ
Registered User
1999 XJ Cherokee 
 
Join Date: Sep 2012
Location: London
Posts: 826
Garage
Can't really add much to that, especially considering what's already been done/changed.
UKXJ is offline  
 
post #4 of 17 Old 03-31-2021, 08:25 AM
Fourspeedman
Registered User
 
Fourspeedman's Avatar
2000 XJ Cherokee 
 
Join Date: May 2018
Location: Queens NY
Posts: 691
When were the lines last bled? I had a problem on the 2012 KK where the brake fluid was original and probably had a lot of moisture. When the caliper got hot the moisture boiled and the gas bubble forced the caliper to close. That created more heat and made the situation even worse. When it cooled down the problem went away. After bleeding all the lines and replacing with DOT 4 fluid that never happened again. I use Castrol DOT 4 because it has a much higher boiling point than DOT 3.

Mark in Queens- Home of Spiderman and the Ramones
Fourspeedman is offline  
post #5 of 17 Old 03-31-2021, 01:35 PM
UKXJ
Registered User
1999 XJ Cherokee 
 
Join Date: Sep 2012
Location: London
Posts: 826
Garage
I thought that nearly every hydraulic component had been changed, so assumed the system had bee comprehensively bled at least once.

I have used DOT4 for years because that's all most parts places stock, in fact it was only recently I learned you could still get DOT3.
UKXJ is offline  
post #6 of 17 Old 03-31-2021, 02:09 PM
Fourspeedman
Registered User
 
Fourspeedman's Avatar
2000 XJ Cherokee 
 
Join Date: May 2018
Location: Queens NY
Posts: 691
Quote:
Originally Posted by UKXJ View Post
I thought that nearly every hydraulic component had been changed, so assumed the system had bee comprehensively bled at least once.
I re-read the first post. You are right- it should have been done. That leaves the caliper itself being the culprit. Rebuilt? Or just swapped over?

Mark in Queens- Home of Spiderman and the Ramones
Fourspeedman is offline  
post #7 of 17 Old 03-31-2021, 03:06 PM Thread Starter
BaileyNB
Registered User
1947 CJ2A 
 
Join Date: Mar 2018
Location: Savannah
Posts: 79
I haven't gotten around to pulling it apart yet to look at anything. Still have a bunch of things I need to do on the house and work as just sucked the dedication to do anything out of me.

It's the original front calipers as far as I know, but I hadn't had any problems with them before. I did bleed the brakes with new DOT 3 fluid since I replaced the proportioning valve with a ZJ valve and master cylinder and booster with one from a 1995 model. I believe it's the original flex lines on the front brakes as well.

Once I get around to it, I'll replace the flex lines for the front and since I'll have to bleed again anyway, replace the back too since I used the donor ZJ's rear flex lines. I'll check the caliper again, but I had no issues pushing the piston back in when I did the original rotor replacement.
BaileyNB is offline  
post #8 of 17 Old 04-02-2021, 04:59 AM
UKXJ
Registered User
1999 XJ Cherokee 
 
Join Date: Sep 2012
Location: London
Posts: 826
Garage
Oh, that old Jeep - v - house battle for time (if not $$'s)! Good luck with that

When you get round to replacing the flexis it wouldn't do any harm to (a) check the calipers are free by removing one pad, depressing the pedal to push the piston most of the way out, inspect, clean, lube, push it back in & press pedal again, work piston back & forth a couple more times (b) double check all the sliding surfaces are clean & lubed to allow caliper to move.
UKXJ is offline  
post #9 of 17 Old 04-02-2021, 11:16 AM Thread Starter
BaileyNB
Registered User
1947 CJ2A 
 
Join Date: Mar 2018
Location: Savannah
Posts: 79
Honestly, for the price of an AC Delco reman caliper with pads from Rock Auto, it's easier if I just replace both the fronts along with the line and call it a day. Then just send the old ones in for the core charge.

Hopefully the instant $7 rebate will still be available. I have to go to *gulp* California for work on Monday, so I won't be placing any orders until next week if I'm lucky and somehow avoid getting stuck in a quarantine situation. Definately don't want auto parts sitting on my front porch for an extra 10 days!

Luckily there's no money issue between house and vehicles, just a time and motivation issue. I bought an old house last June and it needed to be completely rewired. I was finally able to get an electrian to the house to change out the 100 amp service and fuse (yes, fuse) panel for a 200 amp service and circuit breakers. I rewired everything myself, which save a few thousand dollars, but I had to wait until last weekend to rerun the washer and dryer wiring as they are on the back porch and were connected to an external disconnect panel coming directly off the service entry panel. I had to rerun the wiring for the air conditioning today as it was 10ga when it should have been 8ga for the 35 amp breaker, but that should be the last of it. It's honestly a miracle this house never burned down from an electrical fire! But now that it's all done, I can take care of the Jeep when I get home from California and get it out of the way so I have room to work on the shop itself.

Last edited by BaileyNB; 04-02-2021 at 11:17 AM. Reason: typos
BaileyNB is offline  
post #10 of 17 Old 04-16-2021, 06:30 AM Thread Starter
BaileyNB
Registered User
1947 CJ2A 
 
Join Date: Mar 2018
Location: Savannah
Posts: 79
Got everything in the shop ready to put in.

I'm wondering, the brake pads all come with "hardware" but I've never seen it used on the Cherokee. The little metal pieces never seem to show up in any video or tutorial I've seen for changing brakes. Anyone use them?
BaileyNB is offline  
post #11 of 17 Old 04-16-2021, 03:46 PM
UKXJ
Registered User
1999 XJ Cherokee 
 
Join Date: Sep 2012
Location: London
Posts: 826
Garage
Depends on the state of the old ones.

On reflection, as you're dealing with a sticking issue - yeah, use them, after all that may be the root cause of your proble.

Last edited by UKXJ; 04-16-2021 at 03:48 PM. Reason: had 2nd thoughts
UKXJ is offline  
post #12 of 17 Old 04-17-2021, 05:24 AM Thread Starter
BaileyNB
Registered User
1947 CJ2A 
 
Join Date: Mar 2018
Location: Savannah
Posts: 79
How do they get used? As I stated, I've never seen them used and cannot find an image with them installed. The only vehicles I've ever needed to use the brake hardware for are ones that the pads are inserted into a mount and the caliper installed over them as opposed to the pads being installed into the caliper itself.

The pads are resting right onto the arms of the backing plate.
BaileyNB is offline  
post #13 of 17 Old 04-17-2021, 07:30 AM
CJ7-Tim
Real Jeeps have dents
 
CJ7-Tim's Avatar
2000 XJ Cherokee 
 
Join Date: Apr 2002
Location: out in the garage - Minneapolis
Posts: 28,925
Quote:
Originally Posted by BaileyNB View Post
........ the brake pads all come with "hardware" but I've never seen it used on the Cherokee. The little metal pieces never seem to show up in any video or tutorial I've seen for changing brakes. Anyone use them?
Are you describing little metal "tabs" that go on the caliper slide surfaces for some vehicles ? If so, throw them out. None of the 9 XJ Cherokees I have owned had them installed.

If the disk brake pad slide surface is gouged or has wear divots like the picture below, fill them with weld metal and grind them smooth. If the caliper bolts show any wear or corrosion, replace them.



.
Attached Images
 

“We the people are the rightful masters of both Congress and the Courts,
not to overthrow the Constitution but to overthrow the men who would pervert the Constitution” Abraham Lincoln, 1859.
CJ7-Tim is offline  
post #14 of 17 Old 04-17-2021, 08:09 AM
OCDXJ
Registered User
 
OCDXJ's Avatar
2001 XJ Cherokee 
 
Join Date: Aug 2020
Location: East Carbon
Posts: 378
Garage
Quote:
Originally Posted by CJ7-Tim View Post
Are you describing little metal "tabs" that go on the caliper slide surfaces for some vehicles ? If so, throw them out. None of the 9 XJ Cherokees I have owned had them installed. If the disk brake pad slide surface is gouged or has wear divots like the picture below, fill them with weld metal and grind them smooth. If the caliper bolts show any wear or corrosion, replace them.



.
That's interesting, in all the years I have been doing brakes I have never seen a gouge like that, can't even say I remember even seeing wear in that area.

01' XJ, 4.0l, AW4, NP231, D30, CHY8.25, 3" IRO lift, IRO OTK steering, 245/70R16 Nokian Rotiiva AT
OCDXJ is offline  
post #15 of 17 Old 04-17-2021, 11:46 AM Thread Starter
BaileyNB
Registered User
1947 CJ2A 
 
Join Date: Mar 2018
Location: Savannah
Posts: 79
Huh, I thought those little divets were meant to be there. I've seen them on every XJ and YJ I've ever done brakes on or pulled apart from the pull-it yard. It just looked like that was where the pad was suppose to sit. And yes, those little metal tabs are what I was referring to.

I got everything installed now, plus I don't weld, so a little late anyway. I think this is all from the original mess up. The brakes were all working but I had squeel and figured the premature wear or the two year old pads was from the super old, pitted, original rotors. When I replaced the front rotors and pads, I had already put the tires on and lowered the vehicle before pressing the brake pedal and I think the right wheel wasn't mounted quite right. I hit a bump or went over one of the many sets of railroad tracks in my area and I think that caused the rotor shift in place and ride on the dust shield and I think may have caused the dust shield to bend/warp.

After that happened is when I decided to replace the rear drums with discs since I was tearing into it again. I suspect I was still making slight contact, at least on turns, between the rotor and the dust shield. Spinning it by hand I must not have been at the right angle to see and it sounded like normal "singing" from the pads sitting against the rotor. Add that with about 20 miles at highway speeds and it probably overheated the pads during a harder than normal brake and the caliper got stuck.

The only reason I found it this time is that I could hear serious singing after I put everything together. With the wheel straight, no problem, but when I turned it was bad. Turns out that was because I used the new bolts that came with the loaded calipers which 1/4 inch longer than stock and the caliper was shifting! But while I was looking at the right side from underneath the entire hub, I saw a spot where the dust shield was just making contact with the rotor. I took it all apart, beat the lower part of the shield back with a hammer, and when I put everything back together with the stock caliper bolts, it all sounds (and feels) good.

Thanks for the help everyone. I'm not going to worry about the gouges unless something happens again. Everything is sitting right and the gouged area goes beyond where the rotor sits, so I don't think it will affect pad travel. I'm sure something will require me to take everything back apart again in the future, so I'll probably handle it then just to be safe.
BaileyNB is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the JeepForum.com 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 e-mail address for yourself.



Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



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 Off
Pingbacks are On
Refbacks are On

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