Front Brake Dragging

[Strizzo]

I think i have a front passenger brake that is either slow to release or is sticking and dragging. At highway speeds it seems like i am having to steer more and more to the left the longer i'm driving. I thought it was the brake hoses, so I just replaced those last weekend. The problem is persisting, although it is slightly better than it was the other day. It had gotten bad enough that holding the wheel to the left would make the jeep dart left when the brakes were applied and i assume the drag on both wheels evened out.

The primary change was that I did rotors and pads a week or two ago. Caliper pins slide smooth and free and the piston moved back in smoothly when I did the work. During my search on the possible causes I saw that the piston can get stuck and not release sometimes on these after brake pad replacement.

My question is this: How common is it to have a sticking caliper after a brake pad replacement on an otherwise functioning system? Am I looking at the right location for the problem?

Edit: this is on a 2005 4.0/42rle, no abs. Its basically an SE with the 4.0, it was originally sold to a rental fleet in Hawaii.

 

[GregBelleville]

I believe I saw a recent post from the wizard himself that the brakes should be bled prior to compressing the piston to avoid contaminated fluid from causing it to stick.

 

[Harold&Cat]

I've experienced that a few times . With the new pads , the piston is further inside the caliper . If there is rust or dirt on the part of the piston that used to be further out then it can cause sticking once pushed back in .

Also , when pushed back inside the caliper it pushes brake fluid back to the master cylinder . Make sure it's not overfilled with brake fluid .

 

[Strizzo]

I believe I saw a recent post from the wizard himself that the brakes should be bled prior to compressing the piston to avoid contaminated fluid from causing it to stick.

That does make sense. I've bled the brakes now since I replaced the soft lines, which like I said helped but didn't completely fix the issue. I guess some more bathing in brake fluid is in my future.

Were you able to remedy the issue by a solid bleed, or did you have to replace/rebuild the calipers?

 

[Harold&Cat]

I replaced my calipers when they started dragging .

 

[BC Moto]

Same when I noticed the caliper sticking I just changed them out

 

[Rickyd]

If sticking brakes is actually the problem an infrared thermometer can measure your rotors or wheel hubs for a difference in temps.

 

[mrblaine]

That does make sense. I've bled the brakes now since I replaced the soft lines, which like I said helped but didn't completely fix the issue. I guess some more bathing in brake fluid is in my future.

Were you able to remedy the issue by a solid bleed, or did you have to replace/rebuild the calipers?

We had to wire brush and scrape this gunk out of the caliper piston bore. Bleeding beforehand won't always get it done.

 

[Rickyd]

We had to wire brush and scrape this gunk out of the caliper piston bore. Bleeding beforehand won't always get it done.
View attachment 614264

Do you have issues with pulling the piston and reinstalling it with the old seals?

 

[Strizzo]

Do you have issues with pulling the piston and reinstalling it with the old seals?

A caliper rebuild kit is like $4 on rockauto so if I was going that route I'd just refresh everything.

Thanks for all the replies, I ordered new calipers, just wanted to make sure there wasn't something else that could be causing the issue that I missed before firing the parts cannon at it.

 

[Brimstone]

I had the front brakes start dragging on my TJ, it would pull to one side (if I remember correctly it was the right), and the brake on that side would get very hot and start to smell. I disassembled everything, cleaned and greased the slide pins, and reassembled, but within a short time it was dragging again. Which means it was likely the piston/internal seal of the caliper sticking. I ended up replacing the calipers, and the pads & rotors for good measure.

 

[macleanflood]

I had a caliper drag on me after I parked my 97 for a couple of months.

I pulled over... figured out which one was hot, smacked the caliper with a hammer a few times and freed it up

I'd regrease your slide bolts.

-Mac

 

[mrblaine]

I had a caliper drag on me after I parked my 97 for a couple of months.

I pulled over... figured out which one was hot, smacked the caliper with a hammer a few times and freed it up

I'd regrease your slide bolts.

-Mac

I know if you were in there, then you understand that the bolts don't get grease. All the bolts do is clamp the guide sleeves to the knuckle. The guide sleeves live inside a rubber dust boot that pops through the ring cast into the caliper body. When the boot is installed through the ring, then the inside of it where the ridges are inside the ring is where the grease goes before the guide sleeve is pushed through.

 

[BlueC]

I believe I saw a recent post from the wizard himself that the brakes should be bled prior to compressing the piston to avoid contaminated fluid from causing it to stick.

I started doing something like that a few years ago. Every time I do brake work I open the bleed, press the piston back, seal it up and put things back together, then bleed the lines last step. That way if there is any gunk behind the piston it has a chance to be flushed, and I cycle fresh fluid into the system.

 

[Strizzo]

I had a caliper drag on me after I parked my 97 for a couple of months.

I pulled over... figured out which one was hot, smacked the caliper with a hammer a few times and freed it up

I'd regrease your slide bolts.

-Mac

The sleeves move smoothly, with no tears in the boots so no reason to believe they would be sticking. When I swap the calipers though they will be refreshed with them so if there is any issue it will be handled as well.

 

[mrblaine]

I started doing something like that a few years ago. Every time I do brake work I open the bleed, press the piston back, seal it up and put things back together, then bleed the lines last step. That way if there is any gunk behind the piston it has a chance to be flushed, and I cycle fresh fluid into the system.

The problem with doing it that way is you aren't giving yourself the best chance to flush contaminants out of the piston bore. The pic shows a cutaway and how close the piston fits into the bore. Ours are straight bore without the larger area at the base of the bore. When you push the piston in first before flushing, you run a higher risk of trapping gunk that can cause the piston to stick or be sluggish to move and cause drag.

 

[BlueC]

The problem with doing it that way is you aren't giving yourself the best chance to flush contaminants out of the piston bore.

So it would be better to flush the system before doing my current procedure? Or should I be flushing the system in place of opening the bleed before moving the piston back?

 

[Strizzo]

So it would be better to flush the system before doing my current procedure? Or should I be flushing the system in place of opening the bleed before moving the piston back?

I think his recommendation is to bleed/flush the fluid before pushing the piston in, to avoid trapping gunk between the piston and bore before you flush/bleed them.

 

[mrblaine]

I think his recommendation is to bleed/flush the fluid before pushing the piston in, to avoid trapping gunk between the piston and bore before you flush/bleed them.

Avoid would mean it works every time. It doesn't. Sometimes the gunk is like the stuff above and has to be scraped out, flushing first or at any time won't do it. We are just trying to reduce the likelihood of trapping stuff between the piston and bore wall.

 

[Strizzo]

Avoid would mean it works every time. It doesn't. Sometimes the gunk is like the stuff above and has to be scraped out, flushing first or at any time won't do it. We are just trying to reduce the likelihood of trapping stuff between the piston and bore wall.

Right, I understand that is the goal although not foolproof.